Search Results

Search found 3325 results on 133 pages for 'route'.

Page 122/133 | < Previous Page | 118 119 120 121 122 123 124 125 126 127 128 129  | Next Page >

• how does openvpn decide which interface to get IP addrs from

  - by bkrupa

  Using ubuntu 10.04 on both ends. We have a client and server machine on the SAME network attempting to make a vpn connection. We use the config files from here and made minimal changes. The server and client start and seem to connect without any trouble. The server looks like: Wed Feb 23 22:13:22 2011 MULTI: multi_create_instance called Wed Feb 23 22:13:22 2011 192.168.1.55:47166 Re-using SSL/TLS context Wed Feb 23 22:13:22 2011 192.168.1.55:47166 LZO compression initialized Wed Feb 23 22:13:22 2011 192.168.1.55:47166 Control Channel MTU parms [ L:1574 D:138 EF:38 EB:0 ET:0 EL:0 ] Wed Feb 23 22:13:22 2011 192.168.1.55:47166 Data Channel MTU parms [ L:1574 D:1450 EF:42 EB:135 ET:32 EL:0 AF:3/1 ] Wed Feb 23 22:13:22 2011 192.168.1.55:47166 Local Options hash (VER=V4): 'f7df56b8' Wed Feb 23 22:13:22 2011 192.168.1.55:47166 Expected Remote Options hash (VER=V4): 'd79ca330' Wed Feb 23 22:13:22 2011 192.168.1.55:47166 TLS: Initial packet from 192.168.1.55:47166, sid=69112e42 5458135b *...* Wed Feb 23 22:13:22 2011 192.168.1.55:47166 Control Channel: TLSv1, cipher TLSv1/SSLv3 DHE-RSA-AES256-SHA, 1024 bit RSA Wed Feb 23 22:13:22 2011 192.168.1.55:47166 [client1] Peer Connection Initiated with 192.168.1.55:47166 On the client side the connection looks like: Wed Feb 23 22:20:07 2011 [server] Peer Connection Initiated with [AF_INET]192.168.1.41:1194 Wed Feb 23 22:20:10 2011 SENT CONTROL [server]: 'PUSH_REQUEST' (status=1) Wed Feb 23 22:20:10 2011 PUSH: Received control message: 'PUSH_REPLY,route-gateway 10.8.0.4,ping 10,ping-restart 120,ifconfig 10.8.0.50 255.255.255.0' ... Wed Feb 23 22:20:10 2011 /sbin/ifconfig tap0 10.8.0.50 netmask 255.255.255.0 mtu 1500 broadcast 10.8.0.255 Wed Feb 23 22:20:10 2011 Initialization Sequence Completed The openvpn server has been configured to assign ip addresses in the range 10.8.0.* and the client has been given 10.8.0.50. When I run the following nmap from the client: Starting Nmap 5.00 ( http://nmap.org ) at 2011-02-23 22:04 EST Host 10.8.0.50 is up (0.00047s latency). Nmap done: 256 IP addresses (1 host up) scanned in 30.34 seconds Host 192.168.1.1 is up (0.0025s latency). Host 192.168.1.18 is up (0.074s latency). Host 192.168.1.41 is up (0.0024s latency). Host 192.168.1.55 is up (0.00018s latency). Nmap done: 256 IP addresses (4 hosts up) scanned in 6.33 seconds If I run an nmap from the server on 10.8.0.* I get nothing. If the client has two interfaces (wireless and tap device) when you look for a certain ip address, how does it decide which interface to connect on?

  Read the article

• UPS vs Solar Power in case of power failure for a server [on hold]

  - by Zen 8000k

  I am looking for a low power, low end pc able to run 24/7 without overheating and a way to support it in case of power failure. Power failures can be up to 72 hours. The pc dosen't need a monitor or keyboard. A modem must also be protected in case of power failure. When i say low end, i don't mean crap. The cpu needs to be x86 and have at least 1k cpu in this chart: http://www.cpubenchmark.net/index.php What's the best way to do this? EDIT: more info. I need to run a home server. The server will perform light tasks mainly. A x86 cpu sadly is the only route for my use. I want to be able to run the server and the router/modem in case of power failure. Now, regarding how long the power will fail: 1) 1 hours is OK for most situations. (say 90%) 2) 3 hours is OK (say 98%) 3) 6 hours is more thank OK. (say 99.5%) 4) On extreme cases the power might fail days. I believe this is very unlikely to happen. More is great but, really, how ofter power will fail more than 3 hours? I believe once every year at best. Well, that's too rare to care about. Given the above, I am looking for a cost effective way to archive 1-3 hour power or 6 hour if possible. Solutions: You guys give me great ideas. 1) Power generator: no good as power will fail for 10 seconds before returning. Also I read online, "clean" power generators cost 1.5k+, so it's out of budged. Non clean generator might damage electronics, right? 2) Solar power: i don't know for sure about this. Sounds like a great idea, too good to be true, honestly. For only 200$ i get 100+w? What are the drawbacks here? 3) UPS: This seems to be the best. The only problem is the cost. Cost < 200$ = great 400$ = budged limit

  Read the article

• Apache Alias subfolder and starting with dot

  - by MauricioOtta

  I have a multi purpose server running ArchLinux that currently serves multiple virtual hosts from /var/www/domains/EXAMPLE.COM/html /var/www/domains/EXAMPLE2.COM/html I deploy those websites (mostly using Kohana framework) using a Jenkins job by checking out the project, removes the .git folder and ssh-copy the tar.gz to /var/www/domains/ on the server and untars it. Since I don't want to have to re-install phpMyAdmin after each deploy, I decided to use an alias. I would like the alias to be something like /.tools/phpMyAdmin/ so I could have more "tools" later if I wanted to. I have tried just changing the default httpd-phpmyadmin.conf that was installed by following the official WIKI: https://wiki.archlinux.org/index.php/Phpmyadmin Alias /.tools/phpMyAdmin/ "/usr/share/webapps/phpMyAdmin" <Directory "/usr/share/webapps/phpMyAdmin"> AllowOverride All Options FollowSymlinks Order allow,deny Allow from all php_admin_value open_basedir "/var/www/:/tmp/:/usr/share/webapps/:/etc/webapps:/usr/share/pear/" </Directory> Changing only that, doesn't seem to work with my current setup on the server, and apache forwards the request to the framework which 404s (as there's no route to handle /.tools/phpAdmin). I have Mass Virtual hosting enable and setup like this: # # Use name-based virtual hosting. # NameVirtualHost *:8000 # get the server name from the Host: header UseCanonicalName On # splittable logs LogFormat "%{Host}i %h %l %u %t \"%r\" %s %b" vcommon CustomLog logs/access_log vcommon <Directory /var/www/domains> # ExecCGI is needed here because we can't force # CGI execution in the way that ScriptAlias does Options FollowSymLinks ExecCGI AllowOverride All Order allow,deny Allow from all </Directory> RewriteEngine On # a ServerName derived from a Host: header may be any case at all RewriteMap lowercase int:tolower ## deal with normal documents first: # allow Alias /icons/ to work - repeat for other aliases RewriteCond %{REQUEST_URI} !^/icons/ # allow CGIs to work RewriteCond %{REQUEST_URI} !^/cgi-bin/ # do the magic RewriteCond %{SERVER_NAME} ^(www\.|)(.*) RewriteRule ^/(.*)$ /var/www/domains/${lowercase:%2}/html/$1 ## and now deal with CGIs - we have to force a MIME type RewriteCond %{REQUEST_URI} ^/cgi-bin/ RewriteRule ^/(.*)$ /var/www/domains/${lowercase:%{SERVER_NAME}}/cgi-bin/$1 [T=application/x-httpd-cgi] There is also nginx running on this server on port 80 as a reverse proxy for Apache: location ~ \.php$ { proxy_pass http://127.0.0.1:8000; } Everything else was setup by following the official WIKI so I don't think those would cause trouble. Do I need to have the alias for phpMyAdmin setup along the mass virtual hosting or can it be in a separate include file for that alias to work?

  Read the article

• VirtualBox - multiple guests, each with a single bridged adapter?

  - by Martin

  I am running a dedicated server (located at Hetzner, Germany) that runs VirtualBox in order to virtualize several services accross multiple virtual guests. Those guests are supposed to communicate with each other (for instance, a virtual web server has to access a virtual database server); to be reachable from the dedicated server (for instance, SSH access); and to access the Internet via the dedicated server (for instance, to download security updates) Currently, this is achieved by having host-only adapter vboxnet0 on the dedicated server and two virtual interfaces on each guest. There, virtual adapter eth0 is attached to vboxnet0 (to achieve (1) and (2)), virtual adapter eth1 is attached to VirtualBox' NAT (to achieve (3)). Via eth0, the guests have access to a DHCP and a DNS server, both running on the dedicated server (there, bound to vboxnet0). This allows me to assign custom IP addresses and names. Via eth1, VirtualBox pushes a proper route that enables each guest to access the Internet (via eth0 on the dedicated server). This setup with two virtual adapters frequently leads to problems and at leasts complicates many things. For instance, on the dedicated server there is OpenVPN which allows to access the virtual machines via the Internet; futhermore, there is Shorwall that controls the incoming and outgoing network traffic between the Internet, the dedicated server, and the individual virtual machines. Not to mention automatic installation of servers via PXE... Therefore, I would prefer to have only one single virtual adapter on each guest which would be used for both incoming and outgoing connections. As far as I understand, one would basically use a bridged interface for that very purpose. Now the question arises: Which interface on the dedicated server would the bridge use? eth0 on the host server is not an option, as this is prohibited by the provider. A virtual interface eth0:0 would not make any sense, as a bridge always uses a physical interface (eth0 in this case). Would it be possible to create a bridged interface in each virtual machine that would "dangle in the air"? Thus, without a complement on the dedicated server? How would I have to set up the routing on the host server? Please note that the host / dedicated server has only one network adapter (eth0) which is connected to the provider's network. Regards, Martin

  Read the article

• SSH Socks Proxy wiith iptables REDIRECT

  - by Radium

  I have googled and haven`t found the answer on my question. Help me please. There are two servers: serverA with public IP 12.0.0.10 and an private IP 10.0.0.5 serverB with public IP 20.0.0.11 I have setup SOCKS proxy on serverB to serverA: ssh -D20.0.0.11:2222 [email protected] So when on my local machine in a browser i specify SOCKS proxy 20.0.0.11:2222 (serverB:2222) as external IP while browsing i get 12.0.0.10 (serverA IP). That is ok. As well if i go onto http://10.0.0.5 (serverA private IP) it is also reachable. That is what i need. I want to make servers A private IP to be available through servers B public IP on certain ports but without specifying SOCKS in my browser. I could use ssh port forward but the problem is - i need to forward many ports and do not know which exactly - i know only the range. So when i connect to 20.0.0.11 to any port , for example, from 3000:4000 range, i want that traffic to be redirected to 10.0.0.5 on the same port. That is why i`ve decided maybe SOCKS proxy via SSH and iptables REDIRECT could help me. Client - serverBPublicIP (any port from range 3000:4000) - serverAPublicIP - serverAPrivateIP (the port was requested on serverBPublicIP) On serverB i do: ssh -D20.0.0.11:2222 [email protected] iptables -t nat -A PREROUTING -d 20.0.0.11 -p tcp --dport 3000:4000 -j REDIRECT --to-port 2222 But that does not work - when i telnet on 20.0.0.11:3001 for example i do not see any proxied traffic on the serverA. What should i do else? I have tried tcpsocks like this (in example i am telneting to 20.0.0.11:3001) Client -> 20.0.0.11:3001 -> iptables REDIRECT from 3001 --to-port 1111 -> tcpsocks from 1111 to 2222 -> SOCKS proxy from serverB to serverA on port 2222 -> serverA But i do not know what to do with the traffic on serverA. How to route it to its private IP. Help me please. I know, VPN removes all the hell i am trying to create, but i have no ability to use tun/tap device. It is disabled.

  Read the article

• OpenVPN bridged not pinging beyond openvpn server on Ubuntu/Windows 2003

  - by ani

  I set up an OpenVPN server using Ubuntu and a windows server 2003 client to interconnect two networks between two different offices. They can now ping each other, but the rest of the network cannot be contacted by the windows client. Office 1 has internal network of: 192.168.0.0 255.255.240.0 Office 2 has internal network of: 192.168.16.0 255.255.255.0 And the configuration files are: Server.conf port 1194 --script-security 2 up "/etc/openvpn/up.sh br0" down "/etc/openvpn/down.sh br0" # TCP or UDP server? ;proto tcp proto udp dev tap0 ;dev tun ca ca.crt cert openvpn.crt key openvpn.key dh dh1024.pem ifconfig-pool-persist ipp.txt server-bridge 192.168.0.59 255.255.240.0 192.168.6.72 192.168.6.75 push "route 192.168.0.0 255.255.240.0" push "dhcp-option DNS 192.168.0.2" push "dhcp-option DOMAIN testeers.local" keepalive 10 120 tls-auth ta.key 0 # This file is secret comp-lzo user nobody group nogroup persist-key persist-tun log /var/log/openvpn/openvpn.log status /var/log/openvpn-status.log verb 3 Client Config file client dev tap ;dev tun --script-security 2 ;proto tcp proto udp remote 1xx.2xx.xxx.124 1194 resolv-retry infinite nobind persist-key persist-tun ca ca.crt cert admin-VAIO.crt key admin-VAIO.key ns-cert-type server tls-auth ta.key 1 comp-lzo verb 3 Ifconfig on the server now shows the following: br0 Link encap:Ethernet HWaddr 00:50:56:8b:1a:49 inet addr:192.168.0.59 Bcast:192.168.15.255 Mask:255.255.240.0 inet6 addr: fe80::250:56ff:fe8b:1a49/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:1081860 errors:0 dropped:1358 overruns:0 frame:0 TX packets:242385 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:76600615 (76.6 MB) TX bytes:64474575 (64.4 MB) eth0 Link encap:Ethernet HWaddr 00:50:56:8b:1a:49 UP BROADCAST RUNNING PROMISC MULTICAST MTU:1500 Metric:1 RX packets:1144125 errors:0 dropped:7172 overruns:0 frame:0 TX packets:252486 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:109893729 (109.8 MB) TX bytes:66372620 (66.3 MB) lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:67865 errors:0 dropped:0 overruns:0 frame:0 TX packets:67865 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:5183276 (5.1 MB) TX bytes:5183276 (5.1 MB) tap0 Link encap:Ethernet HWaddr 32:4f:42:11:b7:c5 inet6 addr: fe80::304f:42ff:fe11:b7c5/64 Scope:Link UP BROADCAST RUNNING PROMISC MULTICAST MTU:1500 Metric:1 RX packets:3329 errors:0 dropped:0 overruns:0 frame:0 TX packets:215472 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:100 RX bytes:373205 (373.2 KB) TX bytes:17465832 (17.4 MB)

  Read the article

• Is it possible to change an "Unidentified Network" into a "Home" or "Work" network on Windows 7

  - by Rhys

  I have a problem with Windows 7 RC (7100). I frequently use a crossover network cable on WinXP with static IP addresses to connect to various industrial devices (e.g. robots, pumps, valves or even other Windows PCs) that have Ethernet network ports. When I do this on Windows 7, the network connection is classed as an "Unidentified Network" in Networks and Sharing Center and the public firewall profile is enforced by Windows. I do not want to change the public profile and would prefer to use the Home or Work profile instead. For other networks like Home and Work I'm able to click on them and change the classification. This is not available for unidentified networks. My questions are these:- Is there a way to manual override the "Unidentified Network" classification? What tests are performed on the network that fail, therefore classifying it as an "Unidentified Network" By googling (hitting mainly vista issues) it seems that you need to ensure that the default gateway is not 0.0.0.0. I've done this. I've also tried to remove IPv6 but this does not seem possible on Windows 7. UPDATE For those still having problems here is the answer to my issue and the possible reasons why:- Win7 keeps a list of the networks you visit by (I am assuming, but don’t know for sure) the MACID of the device pointed to by the Default Gateway. The default gateway is usually the constant device in a network (i.e. the NAT or router) so can be used to uniquely identify one network from another. The default gateway in the IPv4 properties panel must therefore point to an actual endpoint so windows can then keep track of it. If there is a device at the end of the Default Gateway windows will identify it and track it remembering its settings. The ways you can therefore fool Win7 is to either point the default gateway to your own IP address, or the IP address of the target device you’re communicating with. This will have the side effect of expecting that target device to start routing packets for IP destinations that are outside your subnet. So some applications on Win7 will try to communicate with the internet, these will be passed on to the default gateway (either back you the same IP address or a target device that is not a router) and thus will eventually timeout because neither can route packets. Which you can usually live with. This gets slightly complicated when you mix a this type of connection with a real connection to the internet via WIFI. The wired network card usually has priority when routing because of the “interface metric” so some applications might not connect correctly.

  Read the article

• PSU failing or Mainboard failing?

  - by Andrei Rinea

  I am having some troubles lately powering on my desktop workstation. While starting up the PC after being off for hours (usually at least 8 hours) it randomly fails to do so. What happens is that : I press the power button; nothing happens I can hear a moderate buzzing noise at the back of the PC (near the PSU); but I can't say for sure that it's not from the mainboard. If I insist pressing the power button a few times in 1-2 minutes it'll start Another route would be that instead of (3) I will plug off the power cable from the PSU and wait for 30 seconds. Then I will press the power on and keep it for 30-60 seconds (I had some success at notebooks with a similar approach). Then I will plug back the cable in the PSU, press only once the power button and it will start normally. Also while running normally I keep hearing some low buzzing which seems to be fan-RPM-related (i.e. when processing images or doing CPU intensive work). What should I look into? UPDATE It's getting worse. It took more than 10 retries today and almost 20 minutes to start the computer. I tried the paperclip trick and the PSU behaves perfectly. I managed to start the computer like so : I pressed the on-button a few times and then left the PC in a pre-startup state (the fans were working the buzzing noise was strong and I went to eat. I thought I won't lit the house on fire so fast and without smelling. Back, after 10-15 min the computer booted up! Discussed with a fellow at Intel and he told me the capacitors on the mainboard are probably a bit shot. If they are shot, he said, it should start up warm perfectly. So I did restart it, warm, a few times (5 sec cooldown and then 40 sec cooldown and it started up perfectly). I can either replace the capacitors on the mainboard (doesn't sound worth it or replace the mainboard (this one sucks too :)) ) FINAL INFO : It was the PSU after all. Although it was powering the IDEs and SATAs the Mainboard power module was failing. I bought another mainboard just to find out that this wasn't the cause. Now I'll have to return it somehow. The spare PSU is now in the computer and doing well.. Although larger (500W), it's like a plane taking off.. I need a better one.

  Read the article

• Transient network dropout for Xen DomU's

  - by Stephen C

  We've got a CentOS server running a cluster of virtuals. Occasionally the cluster's internal network drops out for a minute or so ... and then comes back. The problem is somehow related to the actual network traffic, but it is not a simple load issue. (The system is generally lightly loaded, and the problem occurs irrespective of actual load.) The setup: CentOS 5.6 on Dom0, various CentOS on the DomU's Hardware - a Dell R710 with a BroadCom NextXpress 2 NIC (sigh) using the latest drivers for the NIC from BroadCom Xen configured to use network-bridge and vif-bridge Some iptable tweaks to route an unrelated port to one of the virtuals. The system has one externally visible IP address, and Dom0 runs an Apache httpd configured with a number of virtual hosts each of which reverse proxies to web servers running on the virtuals. (The virtuals have to be NAT'ed, primarily because we don't have enough allocated public IP addresses.) The symptoms: Works fine most of the time. When someone tries to UPLOAD a large file to one virtuals, the internal network drops out ... for all virtuals: The Dom0 httpd sees a network timeout talking to the backend server on the virtual and reports a 502. A previously established ssh connection from Dom0 to any of the DomU's freezes. Our monitoring shows ping failures for traffic between virtuals. The Xen consoles to the DomU's do not freeze. No log messages in any log files that I can see, on either Dom0 or the DomU's ... apart from the Dom0 httpd logs. After a minute or so, the problem clears by itself. This is 100% reproducible. What we've tried: Downloading, building and installing the latest BNX2 driver on Dom0 Turning off MSI on the NIC - adding "options bnx2 disable_msi=1" to /etc/modprobe.conf Turning off tcp segmentation offload - "ethtool -K eth0 tso off". Sacrificing a black rooster at midnight. I've exhausted all my options apart from switching to KVM ... or slaughtering more roosters. Any suggestions?

  Read the article

• Assign fixed IP address via DHCP by DNS lookup

  - by Janoszen

  Preface I'm building a virtualization environment with Ubuntu 14.04 and LXC. I don't want to write my own template since the upgrade from 12.04 to 14.04 has shown that backwards compatibility is not guaranteed. Therefore I'm deploying my virtual machines via lxc-create, using the default Ubuntu template. The DNS for the servers is provided by Amazon Route 53, so no local DNS server is needed. I also use Puppet to configure my servers, so I want to keep the manual effort on the deployment minimal. Now, the default Ubuntu template assigns IP addresses via DHCP. Therefore, I need a local DHCP server to assign IP addresses to the nodes, so I can SSH into them and get Puppet running. Since Puppet requires a proper DNS setup, assigning temporary IP addresses is not an option, the client needs to get the right hostname and IP address from the start. Question What DHCP server do I use and how do I get it to assign the IP address based only on the host-name DHCP option by performing a DNS lookup on that very host name? What I've tried I tried to make it work using the ISC DHCP server, however, the manual clearly states: Please be aware that only the dhcp-client-identifier option and the hardware address can be used to match a host declaration, or the host-identifier option parameter for DHCPv6 servers. For example, it is not possible to match a host declaration to a host-name option. This is because the host-name option cannot be guaranteed to be unique for any given client, whereas both the hardware address and dhcp-client-identifier option are at least theoretically guaranteed to be unique to a given client. I also tried to create a class that matches the hostname like this: class "my-client-name" { match if option host-name = "my-client-name"; fixed-address my-client-name.my-domain.com; } Unfortunately the fixed-address option is not allowed in class statements. I can replace it with a 1-size pool, which works as expected: subnet 10.103.0.0 netmask 255.255.0.0 { option routers 10.103.1.1; class "my-client-name" { match if option host-name = "my-client-name"; } pool { allow members of "my-client-name"; range 10.103.1.2 10.103.1.2; } } However, this would require me to administer the IP addresses in two places (Amazon Route53 and the DHCP server), which I would prefer not to do. About security Since this is only used in the bootstrapping phase on an internal network and is then replaced by a static network configuration by Puppet, this shouldn't be an issue from a security standpoint. I am, however, aware that the virtual machine bootstraps with "ubuntu:ubuntu" credentials, which I intend to fix once this is running.

  Read the article

• What the best way to achieve RPO of zero and lowest possible RTO (less than 15 minutes) with SQL 2008 R2?

  - by Adrian Hope-Bailie

  We are running a payments (EFT transaction processing) application which is processing high volumes of transactions 24/7 and are currently investigating a better way of doing DB replication to our disaster recovery site. Our current and previous strategies have included using both DoubleTake and Redgate to replicate data to a warm stand-by. DoubleTake is the supported solution from the payments software vendor however their (DoubleTake's) support in South Africa is very poor. We had a few issues and simply couldn't ever resolve them so we had to give up on DoubleTake. We have been using Redgate to manually read the data from the primary site (via queries) and write to the DR site but this is: A bad solution Getting the software vendor hot and bothered whenever we have support issues as it has a tendency to interfere with the payment application which is very DB intensive. We recently upgraded the whole system to run on SQL 2008 R2 Enterprise which means we should probably be looking at using some of the built-in replication features. The server has 2 fairly large databases with a mixture of tables containing highly volatile transactional data and pretty static configuration data. Replication would be done over a WAN link to a separate physical site and needs to achieve the following objectives. RPO: Zero loss - This is transactional data with financial impact so we can't lose anything. RTO: Tending to zero - The business depends on our ability to process transactions every minute we are down we are losing money I have looked at a few of the other questions/answers but none meet our case exactly: SQL Server 2008 failover strategy - Log shipping or replication? How to achieve the following RTO & RPO with logshipping only using SQL Server? What is the best of two approaches to achieve DB Replication? My current thinking is that we should use mirroring but I am concerned that for RPO:0 we will need to do delayed commits and this could impact the performance of the primary DB which is not an option. Our current DR process is to: Stop incoming traffic to the primary site and allow all in-flight transaction to complete. Allow the replication to DR to complete. Change network routing to route to DR site. Start all applications and services on the secondary site (Ideally we can change this to a warmer stand-by whereby the applications are already running but not processing any transactions). In other words the DR database needs to, as quickly as possible, catch up with primary and be ready for processing as the new primary. We would then need to be able to reverse this when we are ready to switch back. Is there a better option than mirroring (should we be doing log-shipping too) and can anyone suggest other considerations that we should keep in mind?

  Read the article

• routing through multiple subinterfaces in debian

  - by Kstro21

  my question is as simple as the title, i have a debian 6 , 2 NICs, 3 different subnets in a single interface, just like this: auto eth0 iface eth0 inet static address 192.168.106.254 netmask 255.255.255.0 auto eth0:0 iface eth0:0 inet static address 172.19.221.81 netmask 255.255.255.248 auto eth0:1 iface eth0:1 inet static address 192.168.254.1 netmask 255.255.255.248 auto eth1 iface eth1 inet static address 172.19.216.3 netmask 255.255.255.0 gateway 172.19.216.13 eth0 is conected to a swith with 3 differents vlans, eth1 is conected to a router. No iptables DROP, so, all traffic is allowed. Now, passing the traffic through eth0 is OK, passing the traffic through eth0:0 is OK, but, passing the traffic through eth0:1 is not working, i can ping the ip address of that sub interface from a pc where this ip is the default gateway, but can't get to servers in the subnet of the eth1 interface, the traffic is not passing, even when i set the iptables to log all the traffic in the FORWARD chain and i can see the traffic there, but, the traffic is not really passing. And the funny is i can do any the other way around, i mean, passing from eth1 to eth0:1, RDP, telnet, ping, etc, doing some work with the iptable, i manage to pass some traffic from eth0:1 to eth1, the iptables look like this: iptables -t nat PREROUTING -d 192.168.254.1/32 -p tcp -m multiport --dports 25,110,5269 -j DNAT --to-destination 172.19.216.1 iptables -t nat PREROUTING -d 192.168.254.1/32 -p udp -m udp --dport 53 -j DNAT --to-destination 172.19.216.9 iptables -t nat PREROUTING -d 192.168.254.1/32 -p tcp -m tcp --dport 21 -j DNAT --to-destination 172.19.216.11 iptables -t nat POSTROUTING -s 172.19.216.0/24 -d 172.19.221.80/29 -j SNAT --to-source 172.19.221.81 iptables -t nat POSTROUTING -s 172.19.216.0/24 -d 192.168.254.0/29 -j SNAT --to-source 192.168.254.1 iptables -t nat POSTROUTING -s 172.19.216.0/24 -o eth0 -j SNAT --to-source 192.168.106.254 dong this is working, but,it is really a headache have to map each port with the server, imagine if i move the service from server, so, now i have doubts: can debian route through multiple subinterfaces?? exist a limit for this?? if not, what i'm doing wrong when i have the same setup with other subnets and it is working ok?? without the iptables rules in the nat, it doesn't work thanks and i hope good comments/answers

  Read the article

• NIC is receiving, but not transmitting at all?

  - by Shtééf

  I'm trying to fix a very strange problem remotely on a machine at a customer site. The machine is a Dell PowerEdge, I believe a 1950 (haven't verified, but the lspci output matches specs I found.) The machine has two similar NICs, identified as Broadcom Corporation NetXtreme II BCM5708 Gigabit Ethernet (rev 12) by lspci, and using the bnx2 driver. (I suspect these are on-board and on the same controller, which is what I'm accustomed to for this type of machine.) The primary interface eth0 works perfectly, and is in fact how I am ssh'd in. However, the secondary interface eth1 is not transmitting. I can see this in ifconfig output, for example, where the TX field is always 0. However, it is receiving, and tcpdump shows ARP requests coming from the ISP's gateway on the other side. The interface is physically connected to a Siemens BSTU4 modem, configured by the ISP. The link is properly set to 10MBps and full duplex, without negotation, as the ISP requested. A small /30 subnet is configured. For the sake of anonimity, let's say the machine is 3.3.3.2/30, and the ISP's gateway .1. The machine has no firewall settings whatsoever. Even running something like arping -I eth1 3.3.3.1, and running tcpdump alongside, shows no traffic whatsoever being transmitted on the interface. (But the other side keeps steadily sending ARP requests, and that is all that can be seen.) What could be causing this? Here's some output, anonymized, which may hopefully help: $ ethtool eth1 Settings for eth1: Supported ports: [ TP ] Supported link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Full Supports auto-negotiation: Yes Advertised link modes: Not reported Advertised auto-negotiation: No Speed: 10Mb/s Duplex: Full Port: Twisted Pair PHYAD: 1 Transceiver: internal Auto-negotiation: off Supports Wake-on: d Wake-on: d Link detected: yes $ ip link show eth1 3: eth1: <BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast qlen 1000 link/ether 00:15:c5:xx:xx:xx brd ff:ff:ff:ff:ff:ff $ ip -4 addr show eth1 3: eth1: <BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast qlen 1000 inet 3.3.3.2/30 brd 3.3.3.3 scope global eth1 $ ip -4 route show match 3.3.3.0/30 3.3.3.0/30 dev eth1 proto kernel scope link src 3.3.3.2 default via 10.0.0.5 dev eth0

  Read the article

• Second network card configuration not working.

  - by Sebas

  I have 4 servers running Centos 5. All of them have two ethernet network cards. I have configured 192.168.1.x IP addresses on their eth0 card. They are all connected to the same switch using their eth0 card and they are all working. I have configured 10.72.11.x IP addresses on their eth1 card.They are all connected to the same switch - a different one from the switch used with eth0 card - using their eth1 card and they are NOT all working. Their configuration files is like: DEVICE=eth1 BOOTPROTO=static IPADDR=10.72.11.236 BROADCAST=10.72.11.191 NETMASK=255.255.255.192 NETWORK=10.72.11.128 HWADDR=84:2B:2B:55:4B:98 IPV6INIT=yes IPV6_AUTOCONF=yes ONBOOT=yes The interfase is starting and configured as I need. [root@sql1 network-scripts]# ifconfig eth0 Link encap:Ethernet HWaddr 84:2B:2B:55:4B:97 inet addr:192.168.1.105 Bcast:192.168.1.255 Mask:255.255.255.0 inet6 addr: fe80::862b:2bff:fe55:4b97/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:2981 errors:0 dropped:0 overruns:0 frame:0 TX packets:319 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:386809 (377.7 KiB) TX bytes:66134 (64.5 KiB) Interrupt:36 Memory:da000000-da012800 eth1 Link encap:Ethernet HWaddr 84:2B:2B:55:4B:98 inet addr:10.72.11.236 Bcast:10.72.11.191 Mask:255.255.255.192 UP BROADCAST MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:0 (0.0 b) TX bytes:0 (0.0 b) Interrupt:48 Memory:dc000000-dc012800 I also added a route-eth1 file that looks like: 10.0.0.0/8 via 10.72.11.254 Routing looks fine to me: [root@sql1 network-scripts]# netstat -rn Kernel IP routing table Destination Gateway Genmask Flags MSS Window irtt Iface 10.72.11.192 0.0.0.0 255.255.255.192 U 0 0 0 eth1 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth1 10.0.0.0 10.72.11.254 255.0.0.0 UG 0 0 0 eth1 0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 eth0 But I cannot ping one server from the other. [root@sql1 network-scripts]# ping 10.72.11.235 PING 10.72.11.235 (10.72.11.235) 56(84) bytes of data. From 10.72.11.236 icmp_seq=1 Destination Host Unreachable From 10.72.11.236 icmp_seq=2 Destination Host Unreachable From 10.72.11.236 icmp_seq=3 Destination Host Unreachable From 10.72.11.236 icmp_seq=4 Destination Host Unreachable From 10.72.11.236 icmp_seq=5 Destination Host Unreachable From 10.72.11.236 icmp_seq=6 Destination Host Unreachable ^C --- 10.72.11.235 ping statistics --- 7 packets transmitted, 0 received, +6 errors, 100% packet loss, time 6033ms , pipe 3 What am I doing wrong?

  Read the article

• Virtualbox - routing subnet to bridge adapters

  - by user42384

  Hello, I have set up a Debian Lenny box with 3 vbox Lenny machines running eth0 of the host in bridged mode (on virtualbox 3.1.6). When testing in my local LAN, this all worked perfectly well and traffic flowed to and from the IPs of the virtual machines as it should. However, now that it's in its co-lo home, the networking setup is a bit different, and I'm unable to get traffic to flow to the vboxes properly. Specifically, the host has its own Primary IP, and I have a separate subnet of 8 (6 usable) IPs routed to the box for use by the vboxes. So, eth0 on host is: Machine IP: 2x.x.x.137 Gateway IP: 2x.x.x.138 Subnet Msk: 255.255.255.252 Subnet for vboxes is Subnet: 2x.x.x.240/29 Netmask: 255.255.255.248 vbox1 is configured to 2x.x.x.241 on eth0 as follows: auto eth0 iface eth0 inet static address 2x.x.x.241 netmask 255.255.255.248 Setting up a virtual interface (eth0:0) on the host with one of these subnet IPs allows me to ping to that address only from vbox1, and it allows me to ping vbox1 from the host. I can also ping that virtual interface perfectly well from outside, so the IPs are definitely landing at my machine. It seems I'm missing some sort of routing instruction either on the host or vbox1 to get traffic moving between the subnet and the default gateway, but I can't seem to figure out what it should be, or what glaringly obvious thing i'm missing. Most of my obvious attempts (the gw of eth0, the ip of eth0) were rejected by route command with SIOCADDRT: No such device (eg - i can't find it). I tried setting vbox1 to bridge on eth0:0, but this was not an acceptable device name and VBoxHeadless refused to start. The physical machine does have an unused physical NIC at eth1 that can be used if necessary for something or other. Host machine is running iptables configured by ferm, have experimented with it allowing forwarding for that subnet, but I wouldn't have thought this was necessary given the nature of the virtualbox devices (nor did it actually work). Clearing out all of these rules for a blank iptables set does not resolve the issue. (you can see ferm generated iptables at http://codedumper.com/ojaze) Thanks for any help you can give... Patrick

  Read the article

• How to configure DD-WRT routing table when creating an isolated network segment for PCI C VT compliance

  - by tetranz

  I'm the volunteer support and system admin person at a small private school. We need to setup a PCI compliant Windows PC as a virtual terminal for credit card processing. I've read questionnaire SAQ C-VT and, to quote, this computer needs to be accessed: "via a computer that is isolated in a single location, and is not connected to other locations or systems within your environment (this can be achieved via a firewall or network segmentation to isolate the computer from other systems)" Our setup is as follows: DSL modem from ISP is setup to be a "transparent pipe" with no extra services. That goes into the WAN port of Linksys WRT54-GL running a DD-WRT. The LAN is 192.168.1.x. There are a couple of other WRT54-GL / DD-WRT devices. One is used as a wireless AP and another is a client bridge. To isolate the VT (virtual terminal) machine, I have another DD-WRT device. Its WAN is connected to a port on the 192.168.1.x LAN. The virtual terminal machine is connected to its LAN which is at 192.168.10.x. The SPI Firewall etc is turned on. It's basically the default DD-WRT gateway setup where the "ISP" is our own LAN. That's working. All incoming traffic to the VT machine is blocked, including from our own LAN. The VT can access the internet BUT, and here's the problem, it can also ping any of the computers on the 192.168.1.x LAN. I think I need to stop that. I'm guessing that I could do something with the Static Routing table in the VT machine's DD-WRT device. I need to route anything going to 192.168.1.x other than the gateway which is 192.168.1.1 to 0.0.0.0 or something like that. That's where I'm stuck at the end of my knowledge. Or ... do I need to get yet another DD-WRT so the network is "balanced". Maybe I need to have the internet from the DSL going into a DD-WRT which has only two devices on its LAN i.e., two other DD-WRTs, one for the main LAN and one for the VT. I think that would do but I'd like to avoid the extra cost and complexity if I don't need it. Thanks

  Read the article

• Gentoo box can't cURL or ping after restarting net.eth1

  - by Curlybraces

  Hi all, the following is completely baffling me. We currently have a gentoo box which acts as our LAMP, DNS, DHCP server. This is assigned a static IP on the network. This server is connected directly to the internet via a BT BusinessHub Router. The server is also connected to a patch panel/switch port which connects the remaining office (around 10 PC's) to the server. Everything has been plain sailing until the other day when the server was restarted. For some reason now only portions of network accessibility is available depending on which ethernet device was last restarted. Restarting net.eth0 allows the office server to cURL, ping, etc but stops all networked PC's from accessing the internet. Then restarting net.eth1 restores all internet to the network but stops the server from curling, pinging, etc again. However, even when the server can't ping, curl, etc, I can still remote SSH and remote MySQL connect from the server command line to other external servers that we own. Here's my route map (router is 192.168.1.254): Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1 169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth1 127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo 0.0.0.0 192.168.1.254 0.0.0.0 UG 0 0 0 eth1 Here's my /etc/conf.d/net: iface_eth0="192.168.1.99 broadcast 192.168.1.255 netmask 255.255.255.0" iface_eth1="dhcp" None of the above have ever been changed however. Things have just ceased to operate correctly, which makes me think it's a freshly added Iptables rule. Here's the Iptables Filter table: Chain INPUT (policy ACCEPT) target prot opt source destination DROP tcp -- ##.##.##.## anywhere tcp dpt:ssh ACCEPT all -- anywhere anywhere state RELATED,ESTABLISHED ACCEPT all -- anywhere anywhere ACCEPT tcp -- anywhere anywhere tcp dpt:2199 ACCEPT tcp -- anywhere anywhere tcp dpt:3199 ACCEPT tcp -- ##.###.###.## anywhere tcp dpt:http ACCEPT tcp -- ###.###.##.## anywhere tcp dpt:2199 ACCEPT tcp -- ##.###.###.### anywhere tcp dpt:http ACCEPT tcp -- ##.###.##.## anywhere tcp dpt:http ACCEPT tcp -- ##.###.###.### anywhere tcp dpt:3128 ACCEPT udp -- ##.###.###.### anywhere udp dpt:3128 ACCEPT tcp -- ##.###.###.### anywhere tcp dpt:http ACCEPT tcp -- ##.###.###.### anywhere tcp dpt:https Chain FORWARD (policy ACCEPT) target prot opt source destination ACCEPT all -- anywhere ##.###.###.## DROP all -- anywhere ##.###.###.## ACCEPT all -- anywhere anywhere state NEW,ESTABLISHED Chain OUTPUT (policy ACCEPT) target prot opt source destination ACCEPT udp -- anywhere anywhere udp spt:2199 ACCEPT udp -- anywhere anywhere udp spt:4817 ACCEPT udp -- anywhere anywhere udp spt:4819 ACCEPT udp -- anywhere anywhere udp spt:3199 Help gratefully appreciated.

  Read the article

• Nginx Reverse Proxy Node.js and Wordpress + Static Files Issue

  - by joemccann

  I have had quite a time trying to get nginx to serve static assets from my wordpress blog. Have a look at the config and let me know if you can help. ( https://gist.github.com/1130332 - to see the entire thing) server { listen 80; server_name subprint.com; access_log /var/www/subprint/logs/access.log; error_log /var/www/subprint/logs/error.log; root /var/www/subprint/server/public; # express serves static resources for subprint.com out of here location / { proxy_pass http://127.0.0.1:8124; root /var/www/subprint/server; access_log on; } #serve static assets location ~* ^(?!\/).+\.(jpg|jpeg|gif|png|ico|css|zip|tgz|gz|rar|bz2|pdf|txt|tar|wav|bmp|rtf|js|flv|swf|html|htm)$ { expires max; access_log off; } # the route for the wordpress blog # unfortunately the static assets (css, img, etc.) are not being pathed/served properly location /blog { root /var/www/localhost/public; index index.php; access_log /var/www/localhost/logs/access.log; error_log /var/www/localhost/logs/error.log; if (!-e $request_filename) { rewrite ^/(.*)$ /index.php?q=$1 last; break; } if (!-f $request_filename) { rewrite /blog$ /blog/index.php last; break; } } # actually serves the wordpress and subsequently phpmyadmin location ~* (?!\/blog).+\.php$ { fastcgi_pass localhost:9000; fastcgi_index index.php; fastcgi_param SCRIPT_FILENAME /var/www/localhost/public$fastcgi_script_name; fastcgi_param PATH_INFO $fastcgi_script_name; include /usr/local/nginx/conf/fastcgi_params; } # This works fine, but ONLY with a symlink inside the /var/www/localhost/public directory pointing to /usr/share/phpmyadmin location /phpmyadmin { index index.php; access_log /var/www/phpmyadmin/logs/access.log; error_log /var/www/phpmyadmin/logs/error.log; alias /usr/share/phpmyadmin/; if (!-f $request_filename) { rewrite /phpmyadmin$ /phpmyadmin/index.php permanent; break; } } # opt-in to the future add_header "X-UA-Compatible" "IE=Edge,chrome=1"; }

  Read the article

• Network switching issues with MacOS 10.7?

  - by Denis

  I'm having a wired problem and hope somebody can tip me, what way should I dig to. I'm using MacBookPro with Lion 10.7.3 both at my working place & at home. At working place, we have a domain-based network with 802.1x authorization (more than 400 computers) and to connect it I'm using Ethernet cable. IP range is 10.10.2.*. All network settings are setup automatically by DHCP. Also, in settings, I have Network Account Server setup in the User&Groups Settings for my work Domain server - and it is available only from corporate network. At home, I have an ADSL router, that shares Internet connection by WiFi in NAT mode. I'm using WiFi to connect it. Router gives out addresses from 192.168.1.* range and all settings are also set up by router's DHCP. So, my problem is the following. When I come back home from the office, I open my MacBook and AirPort automatically connects my WiFi network. After this, for about 1 minute I'm able to browse sites & ping hosts successfully. But after this minute, network connection is broken down. All pings return time-out. trace route to google.com stops on 192.168.1.1 (which is my router). This lasts for 3-4 minutes. After that network connection is automatically repaired and all pings go smoothly again. At the same time, when my MacBook return timeouts, I can successfully ping any host from my wife's MacBook - so this doesn't look like router issue. When I come to the office, I don't have any issues and Internet connection is available & stable moments after ethernet cable plugged in. Do anybody has any clues about this? What should I monitor & what settings look for resolving this issue? Please, ask, what additional information should I provide. Hoping for good advice & thanks in advance!

  Read the article

• Anti-virus protection question?

  - by DaBaer

  About 4 years ago, I found Kaspersky and have been using the most current version since. Most people try and argue the use of AVG or Avast to me, and there are some very solid reasons I do not go that route. Over the years, I have found Kasp to become bulkier and bulkier, and have had issues setting it up for friends/family/clients. I am just curios on possible recommendations from other users, with my criteria in mind: What I like about Kasp in the past: The license sold in stores in a 3 pack, is considered a commercial license, and emails from Kasp in response to my questions, make it clear that I can do with the 3 licenses that I want, providing I do not use more than 3 installs per Key. So, allowed me to buy 3, 5, and 7 packs, and resell to users at a cheaper cost than what they would pay if they bought their own license. The ability to easily obtain a currently updated .exe for installation on multiple peoples machines. Power of the scan. Kasp has been a good solution for me (even when using a trial license) on cleaning up machines that were badly infected (in which AVG and AVAST were unable to.) Speed of install/update. After a cleanup of malwarebytes, spybot, mcafee stinger, ccleaner, and combofix, I used to be able to get Kasp Int Security installed and updated in around 5 minutes. The issues that I have with the free AV, is strength of protection. In my opinion for someone who is a 'power use' these are good alternatives, because such a user should be trained or knowledgeable enough to be careful and not get themselves in trouble. Most of the users I assist, are too PC ignorant to know any better, and go hogwild on the web. It has been my experience that the number of people coming back to me with spyware/malware/virus issues since I have converted from AVG to Kasp has been cut down to around 20% of what it used to be 4 or 5 years ago. In a perfect world, I could install and use Kasp Internet Security 2008, and be very happy. But this is not the case anymore. So after this long description of what I used, and have used, does anyone have any good recommendations on AV that isn't going to cost me too much per install?

  Read the article

• Managing hosts and iptables in scalable architecture

  - by hakunin

  Let's say I have a load balancer in front of 3 app servers. Let's say I also have these services available at certain IPs: Postgres server Redis server ElasticSearch server Memcached server 1 Memcached server 2 Memcached server 3 So that's 6 nodes at 6 different IP addresses. Naturally, every one of my 3 app servers needs to talk to these 6 servers above. Then, to make it a bit funkier, I also have 3 worker servers. And each worker also talks to the above 6 servers, but thankfully workers and apps never need to talk to each other. Now's the kicker. Everything is on Digital Ocean VPS. What that means is: you have no private network, no private IPs. You only have separate, random IP address on each machine. You can't mask them or anything. So in order to build a secure environment I would have to configure some iptables. For example: Open app servers be accessed by load balancer server Open redis, ES, PG, and each memcached servers to be accessed by each app's IP and each worker's IP This means that every time I add an app or worker I have to also reconfigure iptables in those above 6 servers to welcome the new app or worker. Is there a way to simplify this type of setup? I was thinking — what if there was a gateway machine between apps/workers and the above 6 machines. This way all the interaction would always happen via the gateway server, and when I add a new app or worker I wouldn't need to teach the 6 servers to let it in. If I went this route, then I'd hope a small 512mb server could handle that perhaps, and there wouldn't be almost any overhead. Or would there? Please help with best way to handle this situation. I would appreciate an answer as concrete as possible. I don't think this is too specific, because this general architecture is very common, and Digital Ocean is becoming increasingly popular. A concrete solution here would be much appreciated by many.

  Read the article

• How do you backup 40+ Centos5.5 servers?

  - by John Little

  We are embarrassed to ask this question. Apologies for our lack of UNIX expertise. We have inherited 40+ centos 5.5 servers, and don't know how to back them up. We need low level clone type images so that we could restore the servers from scratch if we had to replace the HDs etc. We have used the "dd" command, but we assume this only works if you want to back up one local disk to another, not 40 servers to one server with an external USB HD attached. All 40 servers have a pair of mirrored disks (dont know if its HW or SW raid). Most only have 100MB used. SErvers are running apache, zend, tomcat, mysql etc. Ideally we dont want to have to shut them down to backup (but could). We assume that standard unix commands like tar, cpio, rsync, scp etc. are of no use as they only copy files, not partitions, all attributes, groups etc. i.e. do not produce a result which can simply be re-imaged to a new HD to get the serer back from dead. We have a large SAN, a spare windows box and spare unix boxes, but these are only visible to one layer in the network. We have an unused Dell DL2000 monster tape unit, but no sw or documentation for it. WE have a copy of symantec backup exec, but we have no budget for unix client licenses. (The company has negative amounts of money). We need to be able to initiate the backup remotely, as we can only access the servers in person in an emergency (i.e. to restore) Googling returns some applications to do this, e.g. clonezilla - looks difficult to install and invasive. Mondo, only seems to support backup if you are local to the machine. Amanda might be an option, but looks like days/weeks of work to learn and setup? Is there anything built into Centos, or do we have to go the route of installing, learning and configuring a set of backup softwares? Any ideas? This must be a pretty standard problem which goggling doesnt give an obvious answer.

  Read the article

• Routing with VPN and asymmetric communication

  - by Louis

  I'm stumbling on a problem that requires your advice. Keywords : networking, route, openVPN Problem : I have a local network with several physical servers and VMs. These machines have ip's in the range 10.10.x.x. I can access these machines from the Internet with the help of openVPN. These machines can : access each other within the local 10.10.x.x subnet access the Internet via the VPN can themselves be accessed (via SSH) from the Internet via the VPN. There is one machine however that behaves strangely and I don't know why. I can SSH into this machine from anywhere via SSH and I can also PING it from anywhere (including the Internet). However from this machine (i.e. when logged into it) I cannot access the Internet or ping machines outside the local network. In other words it will not go beyond the VPN. My question is why? Here are some technical details: The machine's Network Config (running Debian 6.0.3): allow-hotplug eth0 iface eth0 inet static address 10.10.10.200 netmask 255.255.0.0 network 10.10.10.0 broadcast 10.10.10.255 gateway 10.10.10.200 The machine's Routing : Destination Gateway Genmask Flags MSS Window irtt Iface 127.0.0.1 0.0.0.0 255.255.255.255 UH 0 0 0 lo 10.10.0.0 10.10.10.250 255.255.0.0 UG 0 0 0 eth0 10.10.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth0 0.0.0.0 10.10.10.250 0.0.0.0 UG 0 0 0 eth0 0.0.0.0 10.10.10.200 0.0.0.0 UG 0 0 0 eth0 The VPN's Network Config (running Debian 6.0.3): # This is the local network interface auto eth1 allow-hotplug eth1 iface eth1 inet static address 10.10.10.250 netmask 255.255.0.0 broadcast 10.10.10.255 gateway 10.10.10.250 The VPN's routing table Destination Gateway Genmask Flags MSS Window irtt Iface 10.10.0.0 0.0.0.0 255.255.255.0 U 0 0 0 tun0 private 0.0.0.0 255.255.255.0 U 0 0 0 eth0 10.10.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth1 0.0.0.0 10.10.10.250 0.0.0.0 UG 0 0 0 eth1 0.0.0.0 private 0.0.0.0 UG 0 0 0 eth0 net.ipv4.ip_forward = 1 on both machines. there are no iptables set anywhere. Thanks in advance for any feedback.

  Read the article

• iotop for Linux kernel 2.6.18

  - by Lightsauce

  So it has to come to my attention that iotop isn't availalbe for 2.6.18 since it's less than 2.6.20 and requires Python 2.6+. I've done some research and came across this article: http://lserinol.blogspot.com/2009/09/io-usage-per-process-on-linux.html According to this, if these process have io stats in /proc/pid#/io (where pid# is the process #) it's doable regardless of the kernel version. So, in reality, I could upgrade Python to 2.6 and test out iotop. However, my flavor of Linux, CentOS release 5.5 (Final), only supports Python 2.4.3-44.el5 currently. If I were to do uninstall from yum, it doesn't look so pretty. It ends up wanting to uninstall 235 packages, most of which are very important! I read in one place, online (I forget the URL from yesterday), that you can install Python 2.6+ parallel to this one, and have the rpm install for iotop use that. Well, I didn't choose that route. I figured, what the heck, lets write iotop (not copying it, but reverse engineering it without actually looking at it's code/it in use) in bash. I thought it would just grab the /proc/pid#/io file and parse stats. So I wrote a script to grab the top 10 rchar, wchar, read_bytes, and write_bytes by collecting all these stats from all the /proc/pid#/io files, sorting them by each metric, then grabbing the top 10 highest values. The conclusion, the data seems completely useless. Does anybody know any resources for advanced Linux where I can figure out how to take these /proc/pid#/ directories and figure out what the heck they are doing with io on the disk? My main goal is to figure out what exactly is causing high load on my disk. I just know it's on the / partition (/dev/sda2 in this case), and I'm not really sure how to narrow it down without the help of iotop. If I run iostat to grab metrics for 1 minute, every second, the first result it gives me shows a high 'kB_read/s', so that makes me think, it's reading mostly. However, if I watch the update it gives me every second, it's actually just showing values for kB_wrtn/s. This makes me think the initial value iostat gives me is misleading.

  Read the article

• VPC SSH port forward into private subnet

  - by CP510

  Ok, so I've been racking my brain for DAYS on this dilema. I have a VPC setup with a public subnet, and a private subnet. The NAT is in place of course. I can connect from SSH into a instance in the public subnet, as well as the NAT. I can even ssh connect to the private instance from the public instance. I changed the SSHD configuration on the private instance to accept both port 22 and an arbitrary port number 1300. That works fine. But I need to set it up so that I can connect to the private instance directly using the 1300 port number, ie. ssh -i keyfile.pem [email protected] -p 1300 and 1.2.3.4 should route it to the internal server 10.10.10.10. Now I heard iptables is the job for this, so I went ahead and researched and played around with some routing with that. These are the rules I have setup on the public instance (not the NAT). I didn't want to use the NAT for this since AWS apperantly pre-configures the NAT instances when you set them up and I heard using iptables can mess that up. *filter :INPUT ACCEPT [129:12186] :FORWARD ACCEPT [0:0] :OUTPUT ACCEPT [84:10472] -A INPUT -i lo -j ACCEPT -A INPUT -i eth0 -p tcp -m state --state NEW -m tcp --dport 1300 -j ACCEPT -A INPUT -d 10.10.10.10/32 -p tcp -m limit --limit 5/min -j LOG --log-prefix "SSH Dropped: " -A FORWARD -d 10.10.10.10/32 -p tcp -m tcp --dport 1300 -j ACCEPT -A OUTPUT -o lo -j ACCEPT COMMIT # Completed on Wed Apr 17 04:19:29 2013 # Generated by iptables-save v1.4.12 on Wed Apr 17 04:19:29 2013 *nat :PREROUTING ACCEPT [2:104] :INPUT ACCEPT [2:104] :OUTPUT ACCEPT [6:681] :POSTROUTING ACCEPT [7:745] -A PREROUTING -i eth0 -p tcp -m tcp --dport 1300 -j DNAT --to-destination 10.10.10.10:1300 -A POSTROUTING -p tcp -m tcp --dport 1300 -j MASQUERADE COMMIT So when I try this from home. It just times out. No connection refused messages or anything. And I can't seem to find any log messages about dropped packets. My security groups and ACL settings allow communications on these ports in both directions in both subnets and on the NAT. I'm at a loss. What am I doing wrong?

  Read the article

< Previous Page | 118 119 120 121 122 123 124 125 126 127 128 129  | Next Page >