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  • Need IP port forwarding to access an internel service running on an internal machine

    - by appleluo
    I am trying to configure iptables to do port forwarding for certain request. The scenario is like this: Login node A can be accessed from outside Compute node B that running the service can be accessed from A but not from outside. I want to set up iptables so that a request for the service on B from outside can be accessed through A. A has two ethernet ports: Internal eth0, with ip internal_A and External eth1, with ip external_A. B has 1 ethernet port, internal eth0. let's say its ip is internal_B The service listens to internal_B:5900. We open external_A:10000 for user access. I configure my iptables with the following commands: echo 1> /proc/sys/net/ipv4/ip_forward /sbin/iptables -P FORWARD ACCEPT /sbin/iptables -t nat -A POSTROUTING -j MASQUERADE /sbin/iptables -A PREROUTING -p tcp -t nat --dport 10000 -j DNAT --to-destination interal_B:5900 /sbin/iptables -A OUTPUT -p tcp -t nat -d external_A --dport 10000 -j DNAT --to-destination internal_B:5900 But it didn't work. Can anybody help me?

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  • Forward the Wan IP to another Wan IP without changing the source address

    - by user195410
    I have tried this case by using the NAT function in iptables but fail example. PC A IP is 1.1.1.1 (Win7) My Server IP is 2.2.2.2 (CentOS 6.2) target Server B is 3.3.3.3 (Windows server 2003) Flow: PC A WanIP -- My Server A -- Server B (WanIP) My iptables rules: 1. iptables -t nat -A PREROUTING -d 2.2.2.2 -p tcp --dport 80 -j DNAT --to-destination 3.3.3.3:80 2. iptables -t nat -A POSTROUTING -d 2.2.2.2 -j MASQUERADE finally, i can access server B website by enter 2.2.2.2:80 but when i checked the access log at Server B i found it's source address had been changed to src:2.2.2.2 dst:3.3.3.3 please help me to do how to get the real address is src:1.1.1.1 dst:3.3.3.3

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  • firehol (firewall) with bridge: how to filter

    - by Leon
    I have two interfaces: eth0 (public address) and lxcbr0 with 10.0.3.1. I have a LXC guest running with ip 10.0.3.10 This is my firehol config: version 5 trusted_ips=`/usr/local/bin/strip_comments /etc/firehol/trusted_ips` trusted_servers=`/usr/local/bin/strip_comments /etc/firehol/trusted_servers` blacklist full `/usr/local/bin/strip_comments /etc/firehol/blacklist` interface lxcbr0 virtual policy return server "dhcp dns" accept router virtual2internet inface lxcbr0 outface eth0 masquerade route all accept interface any world protection strong #Outgoing these protocols are allowed to everywhere client "smtp pop3 dns ntp mysql icmp" accept #These (incoming) services are available to everyone server "http https smtp ftp imap imaps pop3 pop3s passiveftp" accept #Outgoing, these protocols are only allowed to known servers client "http https webcache ftp ssh pyzor razor" accept dst "${trusted_servers}" On my host I can connect only to "trusted servers" on port 80. In my guest I can connect to port 80 on every host. I assumed that firehol would block that. Is there something I can add/change so that my guest(s) inherit the rules of the eth0 interface?

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  • Strange port forwarding problem

    - by rAyt
    I've got a strange port forwarding problem. The port forwarding to my internal webserver (10.0.0.10 on Port 80) works without a problem but the port forwarding to a windows server (10.0.0.15) on port 3389 doesn't work. The port 3389 is open. Any ideas? thanks! #!/bin/sh IPTABLES="/sbin/iptables" $IPTABLES --flush $IPTABLES --table nat --flush $IPTABLES --delete-chain $IPTABLES --table nat --append POSTROUTING --out-interface eth0 -j MASQUERADE $IPTABLES -t nat -A PREROUTING -p tcp -i eth0 -d 188.40.XXX.XXX --dport 3389 -j DNAT --to 10.0.0.15:3389 $IPTABLES -t nat -A PREROUTING -p tcp -i eth0 -d 188.40.XXX.XXX --dport 80 -j DNAT --to 10.0.0.10:80 $IPTABLES -t nat -A PREROUTING -p tcp -i eth0 -d 188.40.XXX.XXX --dport 222 -j DNAT --to 10.0.0.10:22 $IPTABLES --append FORWARD --in-interface eth1 -j ACCEPT

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  • How can private IPV4 addresses get past iptables NAT (tcp RST,FIN)

    - by gscott
    I've got a router performing simple NAT translation using iptables iptables -t nat -o -j MASQUERADE This works fine almost all of the time except for one particular case where some TCP RST and FIN packets are leaving the router un-NAT'd. In this scenario I setup 1 or 2 client computers streaming Flash video (eg www.nasa.gov/ntv) At the router I then tear down and re-establish the public interface (which is a modem) As expected the Flash streams stall out. After the connection is re-established and I try to refresh the Flash pages, I see some TCP RST and [FIN,ACK] packets leaving the public interface (I assume as Flash attempts to recover its stream). I don't know how these packets can leave the router non-NAT'd

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  • SSH not working over IPSec tunnel (Strongswan)

    - by PattPatel
    I configured a small network on a cloud virtual machine. This virtual machine has a static IP address assigned to eth0 interface that I'll call $EXTIP. mydomain.com points to $EXTIP. Inside, I have some linux containers, that get their ip through DHCP in the Subnet 10.0.0.0/24 (i called the virtual interface nat ). They run some services that can be reached through DNAT. Then I wanted to connect to these containers through an IPSec tunnel, so I configured StrongSwan. ipsec.conf: conn %default dpdaction=none rekey=no conn remote keyexchange=ikev2 ike=######## left=[$EXTIP] leftsubnet=10.0.1.0/24,10.0.0.0/24 leftauth=pubkey lefthostaccess=yes leftcert=########.pem leftfirewall=yes leftid="#########" right=%any rightsourceip=10.0.1.0/24 rightauth=######## rightid=%any rightsendcert=never eap_identity=%any auto=add type=tunnel Everything works fine, IPSec clients get IPs of the 10.0.1.0/24 subnet and can reach the containers subnet. My problem is that I'm not able to get SSH connections over the tunnel. It simply does not work, ssh client does not produce any output. Sniffing with tcpdump gives: tcpdump: 09:50:29.648206 ARP, Request who-has 10.0.0.1 tell mydomain.com, length 28 09:50:29.648246 ARP, Reply 10.0.0.1 is-at 00:ff:aa:00:00:01 (oui Unknown), length 28 09:50:29.648253 IP mydomain.com.54869 > 10.0.0.1.ssh: Flags [S], seq 4007849772, win 29200, options [mss 1460,sackOK,TS val 1151153 ecr 0,nop,wscale 7], length 0 09:50:29.648296 IP 10.0.0.1.ssh > 10.0.1.2.54869: Flags [S.], seq 2809522632, ack 4007849773, win 14480, options [mss 1460,sackOK,TS val 11482992 ecr 1151153,nop,wscale 6], length 0 09:50:29.677225 IP mydomain.com.54869 > 10.0.0.1.ssh: Flags [.], ack 2809522633, win 229, options [nop,nop,TS val 1151162 ecr 11482992], length 0 09:50:29.679370 IP mydomain.com.54869 > 10.0.0.1.ssh: Flags [P.], seq 0:23, ack 1, win 229, options [nop,nop,TS val 1151162 ecr 11482992], length 23 09:50:29.679403 IP 10.0.0.1.ssh > 10.0.1.2.54869: Flags [.], ack 24, win 227, options [nop,nop,TS val 11483002 ecr 1151162], length 0 09:50:29.684337 IP 10.0.0.1.ssh > 10.0.1.2.54869: Flags [P.], seq 1:32, ack 24, win 227, options [nop,nop,TS val 11483003 ecr 1151162], length 31 09:50:29.685471 IP 10.0.0.1.ssh > 10.0.1.2.54869: Flags [.], seq 32:1480, ack 24, win 227, options [nop,nop,TS val 11483003 ecr 1151162], length 1448 09:50:29.685519 IP mydomain.com > 10.0.0.1: ICMP mydomain.com unreachable - need to frag (mtu 1422), length 556 09:50:29.685567 IP 10.0.0.1.ssh > 10.0.1.2.54869: Flags [.], seq 32:1402, ack 24, win 227, options [nop,nop,TS val 11483003 ecr 1151162], length 1370 09:50:29.685572 IP 10.0.0.1.ssh > 10.0.1.2.54869: Flags [.], seq 1402:1480, ack 24, win 227, options [nop,nop,TS val 11483003 ecr 1151162], length 78 09:50:29.714601 IP mydomain.com.54869 > 10.0.0.1.ssh: Flags [.], ack 32, win 229, options [nop,nop,TS val 1151173 ecr 11483003], length 0 09:50:29.714642 IP 10.0.0.1.ssh > 10.0.1.2.54869: Flags [P.], seq 1480:1600, ack 24, win 227, options [nop,nop,TS val 11483012 ecr 1151173], length 120 09:50:29.723649 IP mydomain.com.54869 > 10.0.0.1.ssh: Flags [P.], seq 1393:1959, ack 32, win 229, options [nop,nop,TS val 1151174 ecr 11483003], length 566 09:50:29.723677 IP 10.0.0.1.ssh > 10.0.1.2.54869: Flags [.], ack 24, win 227, options [nop,nop,TS val 11483015 ecr 1151173,nop,nop,sack 1 {1394:1960}], length 0 09:50:29.725688 IP mydomain.com.54869 > 10.0.0.1.ssh: Flags [.], ack 1480, win 251, options [nop,nop,TS val 1151177 ecr 11483003], length 0 09:50:29.952394 IP 10.0.0.1.ssh > 10.0.1.2.54869: Flags [P.], seq 1480:1600, ack 24, win 227, options [nop,nop,TS val 11483084 ecr 1151173,nop,nop,sack 1 {1394:1960}], length 120 09:50:29.981056 IP mydomain.com.54869 > 10.0.0.1.ssh: Flags [.], ack 1600, win 251, options [nop,nop,TS val 1151253 ecr 11483084,nop,nop,sack 1 {1480:1600}], length 0 If you need it this is my iptables configuration file: iptables: *filter :INPUT ACCEPT [144:9669] :FORWARD DROP [0:0] :OUTPUT ACCEPT [97:15649] :interfacce-trusted - [0:0] :porte-trusted - [0:0] -A FORWARD -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT -A FORWARD -j interfacce-trusted -A FORWARD -j porte-trusted -A FORWARD -j REJECT --reject-with icmp-host-unreachable -A FORWARD -d 10.0.0.1/32 -p tcp -m tcp --dport 80 -m state --state NEW,RELATED,ESTABLISHED -j ACCEPT -A FORWARD -d 10.0.0.1/32 -p tcp -m tcp --dport 443 -m state --state NEW,RELATED,ESTABLISHED -j ACCEPT -A FORWARD -d 10.0.0.3/32 -p tcp -m tcp --dport 1234 -m state --state NEW,RELATED,ESTABLISHED -j ACCEPT -A interfacce-trusted -i nat -j ACCEPT -A porte-trusted -d 10.0.0.1/32 -p tcp -m tcp --dport 80 -j ACCEPT -A porte-trusted -d 10.0.0.1/32 -p tcp -m tcp --dport 443 -j ACCEPT -A porte-trusted -d 10.0.0.3/32 -p tcp -m tcp --dport 1234 -j ACCEPT COMMIT *nat :PREROUTING ACCEPT [10:600] :INPUT ACCEPT [10:600] :OUTPUT ACCEPT [4:268] :POSTROUTING ACCEPT [18:1108] -A PREROUTING -d [$EXTIP] -p tcp -m tcp --dport 80 -j DNAT --to-destination 10.0.0.1:80 -A PREROUTING -d [$EXTIP] -p tcp -m tcp --dport 443 -j DNAT --to-destination 10.0.0.1:443 -A PREROUTING -d [$EXTIP] -p tcp -m tcp --dport 8069 -j DNAT --to-destination 10.0.0.3:1234 -A POSTROUTING -s 10.0.0.0/24 -o eth0 -m policy --dir out --pol ipsec -j ACCEPT -A POSTROUTING -s 10.0.1.0/24 -o nat -j MASQUERADE -A POSTROUTING -s 10.0.0.0/24 -o eth0 -j MASQUERADE COMMIT Probably I'm missing something stupid... Thanks in advance for helping :))

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  • Ubuntu Server UFW NAT Issues

    - by William Fleming
    *nat :POSTROUTING ACCEPT [0:0] -A POSTROUTING -s 10.8.0.0/24 -o eth0 -j MASQUERADE -A ufw-before-input -i tun0 -j ACCEPT -A ufw-before-output -i tun0 -j ACCEPT -A ufw-before-forward -s 10.8.0.0/24 -j ACCEPT -A ufw-before-forward -d 10.8.0.0/24 -j ACCEPT This input into my before.rules file stops me being able to ping the outside world. Before its fine i can ping google.co.uk after cant get out. Is there something wrong in my syntax here or what is the issue...? Im just trying to NAT my VPN so i can get internet access. Any thoughts would be greatly appreciated. Thanks William

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  • ipfw to redirect traffic from port 80 and 443 to 8080

    - by user1048138
    -A PREROUTING -s 10.0.10.0/24 -p tcp -m tcp --dport 80 -j REDIRECT --to-ports 8080 -A PREROUTING -s 10.0.10.0/24 -p tcp -m tcp --dport 443 -j REDIRECT --to-ports 8080 -A POSTROUTING -s 10.0.10.0/24 -o eth0 -j MASQUERADE The above code is what I have used on linux to forward my ports to 8080, how can I do the same on a mac? I have tried test_machine:~ root# ipfw show 00666 0 0 fwd 127.0.0.1,8080 tcp from any to me dst-port 80 and its not working! any suggestions?

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  • Iptables based router inside KVM virtual machine

    - by Anton
    I have KVM virtual machine (CentOS 6.2 x64), it has 2 NIC: eth0 - real external IP 1.2.3.4 (simplified example instead of real one) eth1 - local internal IP 172.16.0.1 Now I'm trying to make port mapping 1.2.3.4:80 = 172.16.0.2:80 Current iptables rules: # Generated by iptables-save v1.4.7 on Fri Jun 29 17:53:36 2012 *nat :OUTPUT ACCEPT [0:0] :PREROUTING ACCEPT [0:0] :POSTROUTING ACCEPT [0:0] -A POSTROUTING -o eth0 -j MASQUERADE -A PREROUTING -p tcp -m tcp -d 1.2.3.4 --dport 80 -j DNAT --to-destination 172.16.0.2:80 COMMIT # Completed on Fri Jun 29 17:53:36 2012 # Generated by iptables-save v1.4.7 on Fri Jun 29 17:53:36 2012 *mangle :PREROUTING ACCEPT [0:0] :INPUT ACCEPT [0:0] :FORWARD ACCEPT [0:0] :OUTPUT ACCEPT [0:0] :POSTROUTING ACCEPT [0:0] COMMIT # Completed on Fri Jun 29 17:53:36 2012 # Generated by iptables-save v1.4.7 on Fri Jun 29 17:53:36 2012 *filter :INPUT ACCEPT [0:0] :FORWARD ACCEPT [0:0] :OUTPUT ACCEPT [0:0] COMMIT # Completed on Fri Jun 29 17:53:36 2012 But there is nothing works, I mean it does not forwards that port. Similar configuration without virtualization seems to be working. What am I missing? Thanks!

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  • Basic networking: Centos Server Router + Ubuntu Client setup.. unable to access outside world from client

    - by ale
    I am trying to set up my Centos Server with two NICs as a router. eth0 is connected to the outside world and eth1 is connected to an Ubuntu client. Here's eth0 on the server: DEVICE=eth0 BOOTPROTO=dhcp ONBOOT=yes TYPE=Ethernet eth1 on the server: DEVICE=eth1 BOOTPROTO=static IPADDR=192.168.0.10 # a free address on my network ONBOOT=yes TYPE=Ethernet My server has IPv4 packet forwarding turned on and my iptables only contains: # iptables --table nat --append POSTROUTING --out-interface eth0 -j MASQUERADE # iptables --append FORWARD --in-interface eth1 -j ACCEPT My Ubuntu client has this in its /etc/network/interfaces auto lo iface lo inet loopback iface eth0 inet dhcp gateway 192.168.0.10 but I can't get an Internet connection from the server for my client. I can't even ping my server from the client: $ ping 192.168.0.10 Destination Host Unreachable

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  • IPTables reroute traffic not working

    - by user1307079
    I am trying to reroute incoming traffic on my server's port 80 to another server, but it is not working. This is what I tried. On the host server, I ran these: echo “1? > /proc/sys/net/ipv4/ip_forward iptables -t nat -A PREROUTING -p tcp --dport 80 -j DNAT --to-destination 38.105.20.226:80 iptables -t nat -A POSTROUTING -j MASQUERADE The server I want it to redirect to is 38.105.20.226:80, but when I go to the webserver that is on the main server, instead of showing the content of the web server on 38.105.20.226:80, it just doesn't load. I am on CentOS.

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  • iptables question

    - by RubyFreak
    i have a small network, with one valid IP and a firewall with 3 network interfaces (LAN, WAN, DMZ). I want to enable PAT on this valid IP to redirect http traffic to a server in my DMZ. (done) I want to enable MASQ on this ip from traffic that comes from my LAN (done) I want from my LAN as well to access my http server at DMZ. (partially) Question: in the above scenario, i cannot from my LAN, to access my http server in the DMZ, since it has the IP used by the MASQ (the only valid ip that i have). What would be the best option to solve this problem? network interfaces: eth0 (WAN) eth1 (DMZ) eth2 (LAN) /sbin/iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE /sbin/iptables -A FORWARD --o eth1 -d 2.2.2.2 -p tcp --dport 80 -j ACCEPT /sbin/iptables -t nat -A PREROUTING -i eth0 -d 1.1.1.1 -p tcp --dport 80 -j DNAT --to 2.2.2.2 /sbin/iptables -A FORWARD -i eth0 -o eth1 -m state --state RELATED,ESTABLISHED -j ACCEPT /sbin/iptables -A FORWARD -i eth1 -o eth0 -j ACCEPT /sbin/iptables -A FORWARD -i eth2 -o eth0 -j ACCEPT

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  • Is there an equivalent of SU for Windows

    - by CodeSlave
    Is there a way (when logged in as an administrator, or as a member of the administrators group) to masquerade as a non-privileged user? Especially in an AD environment. e.g., in the Unix world I could do the following (as root): # whoami root # su johnsmith johnsmith> whoami johnsmith johnsmith> exit # exit I need to test/configure something on a user's account, and I don't want to have to know their password or have to reset it. Edit: runas won't cut it. Ideally, my whole desktop would become the user's, etc. and not just in a cmd window.

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  • Attempting to caue packet loss with netem doesn't work - possibly because of NAT (but delay does work)

    - by tomdee
    I have traffic from a WIFI access point routed via an Ubuntu box. I have two network interfaces which are NATed *filter :INPUT ACCEPT [11:690] :FORWARD ACCEPT [0:0] :OUTPUT ACCEPT [37:6224] -A FORWARD -s 192.168.2.0/24 -i eth1 -o eth0 -m conntrack --ctstate NEW -j ACCEPT -A FORWARD -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT COMMIT # Completed on Thu Mar 15 13:37:21 2012 # Generated by iptables-save v1.4.10 on Thu Mar 15 13:37:21 2012 *nat :PREROUTING ACCEPT [0:0] :INPUT ACCEPT [0:0] :OUTPUT ACCEPT [0:0] :POSTROUTING ACCEPT [0:0] -A POSTROUTING -j MASQUERADE COMMIT If I run a ping app on an Android device connected to the WIFI network I can happily ping google. If I use netem to introduce some delay tc qdisc change dev eth0 root netem delay 100ms I can clearly see pings taking longer. If I use netem to introduce some packet loss tc qdisc change dev ifb0 root netem loss 50% then I see no change. Packet loss does work fine for locally generated traffic, just not for traffic coming in over the network that's being NATed. Any ideas how to sort this out?

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  • Linux + IPTables + NAT = some http hosts unreachable.

    - by Daniel
    Hi. I've set up dead simple NAT: iptables -t nat -A POSTROUTING -s 192.168.1.0/24 -o ppp0 -j MASQUERADE Everything works almost ok. Almost. The problem I've expirienced is some hosts are not reachable by NAT clients, i.e. there's http://code.jquery.com/jquery-1.4.2.min.js - I can download it from server, but in case of NAT client download stalls on connection stage. I thought its FFs fault, but wget has the same issue. I didn't find any logs/messages that can shed some light on this situtation. Any ideas what's going on? Maybe some tricky thing in sysclt is causing this? P.S. 3/3 client boxes are expiriencing this issue. This is definitely server trouble.

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  • Iptables NAT logging

    - by Gerard
    I have a box setup as a router using Iptables (masquerade), logging all network traffic. The problem: Connections from LAN IPs to WAN show fine, i.e. SRC=192.168.32.10 - DST=60.242.67.190 but for traffic coming from WAN to LAN it will show the WAN IP as the source, but the routers IP as the destination, then the router - LAN IP. I.e. SRC=60.242.67.190 - DST=192.168.32.199 SRC=192.168.32.199(router) - DST=192.168.32.10 How do I configure it so that it logs the conversations correctly? SRC=192.168.32.10 - DST=60.242.67.190 SRC=60.242.67.190 DST=192.168.32.10 Any help appreciated, cheers

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  • I need to somehow change my ip address

    - by tric
    hello. i`m in a lan using iptables/masquerade. what i want to do, is to login in a web application.i write my user and passwd and click login and everything is fine, but if i try to modify something in that aplication it tells me that i have a wrong ip address.i knwo for sure that this app only allows ip 10.3.x.x .how can i trick that application to think that i have an ip from class 10.3.x.x and not my wan ip? 10x sorry for my bad english!

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  • Cannot redirect ip traffic with iptables to new ip on linux centOS

    - by Kiwi
    today I able to migrate some of the game servers to another server and needed some help to redirect the traffic from old ip to the new one. SERVER1 1.1.1.1 ----- (internet ) ----- SERVER 2.2.2.2 I asume to use iptables to perform this, for that used this rule on my centOS box in the server1. /etc/sysctl.conf: net.ipv4.ip_forward = 1 iptables -t nat -A PREROUTING -p udp --dest 1.1.1.1 --dport 27015 -j DNAT --to-destination 2.2.2.2:27015 iptables -t nat -A POSTROUTING -j MASQUERADE iptables -t nat -A POSTROUTING -d 2.2.2.2 -p udp --dport 27015 -j SNAT --to 1.1.1.1 But the client cannot connect to the server from the old ip, the redirection don't started.

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  • Linux router with diffent gateways for incomming and outgoing connections

    - by nkout
    I have the following topology: LAN Users:192.168.1.2 - 254 (192.168.1.0/24) gateway1: 192.168.2.2/24 used for all outgoing connections of LAN users (default gateway) gateway2: 192.168.3.2/24 used for incoming services (destination NAT, ports 80,443 are forwarded to 192.168.2.1) linux router-server R eth0 192.168.1.1/24: LAN eth1 192.168.2.1/24: WWAN1 eth2 192.168.3.1/24: WWAN2 I want to: route all outgoing traffic coming from LAN and R via 192.168.2.2 route the responses to incoming connections via 192.168.3.2 My config: ifconfig eth0 up 192.168.1.1 netmask 255.255.255.0 ifconfig eth1 up 192.168.2.1 netmask 255.255.255.0 ifconfig eth2 up 192.168.3.1 netmask 255.255.255.0 echo 0 >/proc/sys/net/ipv4/ip_forward route add default gw 192.168.2.2 iptables -t nat -A POSTROUTING -d !192.168.0.0/16 -j MASQUERADE I want to add iptables rule to mark incoming traffic from WWAN2 and send back the responses to WWAN2, while keeping default gateway on WWAN1

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  • How do I bridge connections in Debian?

    - by Josh
    In windows I can select Local Area Connection and Wireless Network Connection, right click and select Bridge Connections How can I achieve the same effect in Linux? (Debian to be exact) Pretty much I want Computer B to connect to Computer A via ethernet cable. Well Computer A is connected wirelessly. Allowing Computer B to get on the internet. == UPDATE == I've enabled IP forwarding and used the following iptables command: iptables -t nat -A POSTROUTING -o wlan0 -j MASQUERADE I'm still unable to access the internet from Computer B though.

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  • nat with iptables, re-connecting fail within about 3 minutes

    - by xpu
    i constructed a nat with iptables, as following: echo 1 > /proc/sys/net/ipv4/ip_forward iptables -t nat -I PREROUTING -p tcp --dport 9000 -j DNAT --to xx.xx.xx.xx iptables -t nat -I POSTROUTING -p tcp --dport 9000 -j MASQUERADE service iptables save service iptables restart the configuration worked fine, but there was a problem when i disconnected and tried to reconnect again, connection will be refused within about 2~3 minutes, after that, things go fine again. what was the problem? how do i make it to accept new connection after the old one break?

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  • How to deal with redirect traffic in widows2003

    - by Huiyu
    I have set up an OpenVPN server on Windows 2003, and I want to route all client traffic through the VPN, so that my clients can connect to the Internet through the VPN server. In the server configuration, I added push "redirect-gateway def1". I know the server needs to be configured to deal with the traffic somehow: for example, on Linux, I can use iptables -t nat -A POSTROUTING -s 10.8.0.0/24 -o eth0 -j MASQUERADE. The problem is, I don't know how to deal with the traffic on Windows Server 2003. Is there any way to accomplish this?

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  • PPTP VPN Server issue : server = centOS & client = windows 7

    - by jmassic
    I have a CentOS server configured as a PPTP VPN Server. The client is a Windows 7 with "Use default gateway on remote network" in advanced TCP/IPv4 properties enable. He can connect to CentOS without any problem and can access to: The Box of his ISP (http://192.168.1.254/) The CentOS server The website which is hosted by the server (through http://) But he canNOT access any other web service (google.com or 74.125.230.224) I am a beginner with web servers so I do not know what can cause this problem. Note 0 : The Windows 7 user must be able to access the whole internet through the CentOS PPTP proxy. Note 1 : With "Use default gateway on remote network" in advanced TCP/IPv4 UNCHECKED it is the same problem Note 2 : With "Use default gateway on remote network" in advanced TCP/IPv4 UNCHECKED AND "disable class based route addition" CHECKED the Win 7 can access google but with the ISP IP (no use of the VPN...) See Screenshot Note 3 : I have made a echo 1 > /proc/sys/net/ipv4/ip_forward and a iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE

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  • Connecting Linux to WatchGuard Firebox SSL (OpenVPN client)

    Recently, I got a new project assignment that requires to connect permanently to the customer's network through VPN. They are using a so-called SSL VPN. As I am using OpenVPN since more than 5 years within my company's network I was quite curious about their solution and how it would actually be different from OpenVPN. Well, short version: It is a disguised version of OpenVPN. Unfortunately, the company only offers a client for Windows and Mac OS which shouldn't bother any Linux user after all. OpenVPN is part of every recent distribution and can be activated in a couple of minutes - both client as well as server (if necessary). WatchGuard Firebox SSL - About dialog Borrowing some files from a Windows client installation Initially, I didn't know about the product, so therefore I went through the installation on Windows 8. No obstacles (and no restart despite installation of TAP device drivers!) here and the secured VPN channel was up and running in less than 2 minutes or so. Much appreciated from both parties - customer and me. Of course, this whole client package and my long year approved and stable installation ignited my interest to have a closer look at the WatchGuard client. Compared to the original OpenVPN client (okay, I have to admit this is years ago) this commercial product is smarter in terms of file locations during installation. You'll be able to access the configuration and key files below your roaming application data folder. To get there, simply enter '%AppData%\WatchGuard\Mobile VPN' in your Windows/File Explorer and confirm with Enter/Return. This will display the following files: Application folder below user profile with configuration and certificate files From there we are going to borrow four files, namely: ca.crt client.crt client.ovpn client.pem and transfer them to the Linux system. You might also be able to isolate those four files from a Mac OS client. Frankly, I'm just too lazy to run the WatchGuard client installation on a Mac mini only to find the folder location, and I'm going to describe why a little bit further down this article. I know that you can do that! Feedback in the comment section is appreciated. Configuration of OpenVPN (console) Depending on your distribution the following steps might be a little different but in general you should be able to get the important information from it. I'm going to describe the steps in Ubuntu 13.04 (Raring Ringtail). As usual, there are two possibilities to achieve your goal: console and UI. Let's what it is necessary to be done. First of all, you should ensure that you have OpenVPN installed on your system. Open your favourite terminal application and run the following statement: $ sudo apt-get install openvpn network-manager-openvpn network-manager-openvpn-gnome Just to be on the safe side. The four above mentioned files from your Windows machine could be copied anywhere but either you place them below your own user directory or you put them (as root) below the default directory: /etc/openvpn At this stage you would be able to do a test run already. Just in case, run the following command and check the output (it's the similar information you would get from the 'View Logs...' context menu entry in Windows: $ sudo openvpn --config client.ovpn Pay attention to the correct path to your configuration and certificate files. OpenVPN will ask you to enter your Auth Username and Auth Password in order to establish the VPN connection, same as the Windows client. Remote server and user authentication to establish the VPN Please complete the test run and see whether all went well. You can disconnect pressing Ctrl+C. Simplifying your life - authentication file In my case, I actually set up the OpenVPN client on my gateway/router. This establishes a VPN channel between my network and my client's network and allows me to switch machines easily without having the necessity to install the WatchGuard client on each and every machine. That's also very handy for my various virtualised Windows machines. Anyway, as the client configuration, key and certificate files are located on a headless system somewhere under the roof, it is mandatory to have an automatic connection to the remote site. For that you should first change the file extension '.ovpn' to '.conf' which is the default extension on Linux systems for OpenVPN, and then open the client configuration file in order to extend an existing line. $ sudo mv client.ovpn client.conf $ sudo nano client.conf You should have a similar content to this one here: dev tunclientproto tcp-clientca ca.crtcert client.crtkey client.pemtls-remote "/O=WatchGuard_Technologies/OU=Fireware/CN=Fireware_SSLVPN_Server"remote-cert-eku "TLS Web Server Authentication"remote 1.2.3.4 443persist-keypersist-tunverb 3mute 20keepalive 10 60cipher AES-256-CBCauth SHA1float 1reneg-sec 3660nobindmute-replay-warningsauth-user-pass auth.txt Note: I changed the IP address of the remote directive above (which should be obvious, right?). Anyway, the required change is marked in red and we have to create a new authentication file 'auth.txt'. You can give the directive 'auth-user-pass' any file name you'd like to. Due to my existing OpenVPN infrastructure my setup differs completely from the above written content but for sake of simplicity I just keep it 'as-is'. Okay, let's create this file 'auth.txt' $ sudo nano auth.txt and just put two lines of information in it - username on the first, and password on the second line, like so: myvpnusernameverysecretpassword Store the file, change permissions, and call openvpn with your configuration file again: $ sudo chmod 0600 auth.txt $ sudo openvpn --config client.conf This should now work without being prompted to enter username and password. In case that you placed your files below the system-wide location /etc/openvpn you can operate your VPNs also via service command like so: $ sudo service openvpn start client $ sudo service openvpn stop client Using Network Manager For newer Linux users or the ones with 'console-phobia' I'm going to describe now how to use Network Manager to setup the OpenVPN client. For this move your mouse to the systray area and click on Network Connections => VPN Connections => Configure VPNs... which opens your Network Connections dialog. Alternatively, use the HUD and enter 'Network Connections'. Network connections overview in Ubuntu Click on 'Add' button. On the next dialog select 'Import a saved VPN configuration...' from the dropdown list and click on 'Create...' Choose connection type to import VPN configuration Now you navigate to your folder where you put the client files from the Windows system and you open the 'client.ovpn' file. Next, on the tab 'VPN' proceed with the following steps (directives from the configuration file are referred): General Check the IP address of Gateway ('remote' - we used 1.2.3.4 in this setup) Authentication Change Type to 'Password with Certificates (TLS)' ('auth-pass-user') Enter User name to access your client keys (Auth Name: myvpnusername) Enter Password (Auth Password: verysecretpassword) and choose your password handling Browse for your User Certificate ('cert' - should be pre-selected with client.crt) Browse for your CA Certificate ('ca' - should be filled as ca.crt) Specify your Private Key ('key' - here: client.pem) Then click on the 'Advanced...' button and check the following values: Use custom gateway port: 443 (second value of 'remote' directive) Check the selected value of Cipher ('cipher') Check HMAC Authentication ('auth') Enter the Subject Match: /O=WatchGuard_Technologies/OU=Fireware/CN=Fireware_SSLVPN_Server ('tls-remote') Finally, you have to confirm and close all dialogs. You should be able to establish your OpenVPN-WatchGuard connection via Network Manager. For that, click on the 'VPN Connections => client' entry on your Network Manager in the systray. It is advised that you keep an eye on the syslog to see whether there are any problematic issues that would require some additional attention. Advanced topic: routing As stated above, I'm running the 'WatchGuard client for Linux' on my head-less server, and since then I'm actually establishing a secure communication channel between two networks. In order to enable your network clients to get access to machines on the remote side there are two possibilities to enable that: Proper routing on both sides of the connection which enables both-direction access, or Network masquerading on the 'client side' of the connection Following, I'm going to describe the second option a little bit more in detail. The Linux system that I'm using is already configured as a gateway to the internet. I won't explain the necessary steps to do that, and will only focus on the additional tweaks I had to do. You can find tons of very good instructions and tutorials on 'How to setup a Linux gateway/router' - just use Google. OK, back to the actual modifications. First, we need to have some information about the network topology and IP address range used on the 'other' side. We can get this very easily from /var/log/syslog after we established the OpenVPN channel, like so: $ sudo tail -n20 /var/log/syslog Or if your system is quite busy with logging, like so: $ sudo less /var/log/syslog | grep ovpn The output should contain PUSH received message similar to the following one: Jul 23 23:13:28 ios1 ovpn-client[789]: PUSH: Received control message: 'PUSH_REPLY,topology subnet,route 192.168.1.0 255.255.255.0,dhcp-option DOMAIN ,route-gateway 192.168.6.1,topology subnet,ping 10,ping-restart 60,ifconfig 192.168.6.2 255.255.255.0' The interesting part for us is the route command which I highlighted already in the sample PUSH_REPLY. Depending on your remote server there might be multiple networks defined (172.16.x.x and/or 10.x.x.x). Important: The IP address range on both sides of the connection has to be different, otherwise you will have to shuffle IPs or increase your the netmask. {loadposition content_adsense} After the VPN connection is established, we have to extend the rules for iptables in order to route and masquerade IP packets properly. I created a shell script to take care of those steps: #!/bin/sh -eIPTABLES=/sbin/iptablesDEV_LAN=eth0DEV_VPNS=tun+VPN=192.168.1.0/24 $IPTABLES -A FORWARD -i $DEV_LAN -o $DEV_VPNS -d $VPN -j ACCEPT$IPTABLES -A FORWARD -i $DEV_VPNS -o $DEV_LAN -s $VPN -j ACCEPT$IPTABLES -t nat -A POSTROUTING -o $DEV_VPNS -d $VPN -j MASQUERADE I'm using the wildcard interface 'tun+' because I have multiple client configurations for OpenVPN on my server. In your case, it might be sufficient to specify device 'tun0' only. Simplifying your life - automatic connect on boot Now, that the client connection works flawless, configuration of routing and iptables is okay, we might consider to add another 'laziness' factor into our setup. Due to kernel updates or other circumstances it might be necessary to reboot your system. Wouldn't it be nice that the VPN connections are established during the boot procedure? Yes, of course it would be. To achieve this, we have to configure OpenVPN to automatically start our VPNs via init script. Let's have a look at the responsible 'default' file and adjust the settings accordingly. $ sudo nano /etc/default/openvpn Which should have a similar content to this: # This is the configuration file for /etc/init.d/openvpn## Start only these VPNs automatically via init script.# Allowed values are "all", "none" or space separated list of# names of the VPNs. If empty, "all" is assumed.# The VPN name refers to the VPN configutation file name.# i.e. "home" would be /etc/openvpn/home.conf#AUTOSTART="all"#AUTOSTART="none"#AUTOSTART="home office"## ... more information which remains unmodified ... With the OpenVPN client configuration as described above you would either set AUTOSTART to "all" or to "client" to enable automatic start of your VPN(s) during boot. You should also take care that your iptables commands are executed after the link has been established, too. You can easily test this configuration without reboot, like so: $ sudo service openvpn restart Enjoy stable VPN connections between your Linux system(s) and a WatchGuard Firebox SSL remote server. Cheers, JoKi

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  • New Big Data Appliance Security Features

    - by mgubar
    The Oracle Big Data Appliance (BDA) is an engineered system for big data processing.  It greatly simplifies the deployment of an optimized Hadoop Cluster – whether that cluster is used for batch or real-time processing.  The vast majority of BDA customers are integrating the appliance with their Oracle Databases and they have certain expectations – especially around security.  Oracle Database customers have benefited from a rich set of security features:  encryption, redaction, data masking, database firewall, label based access control – and much, much more.  They want similar capabilities with their Hadoop cluster.    Unfortunately, Hadoop wasn’t developed with security in mind.  By default, a Hadoop cluster is insecure – the antithesis of an Oracle Database.  Some critical security features have been implemented – but even those capabilities are arduous to setup and configure.  Oracle believes that a key element of an optimized appliance is that its data should be secure.  Therefore, by default the BDA delivers the “AAA of security”: authentication, authorization and auditing. Security Starts at Authentication A successful security strategy is predicated on strong authentication – for both users and software services.  Consider the default configuration for a newly installed Oracle Database; it’s been a long time since you had a legitimate chance at accessing the database using the credentials “system/manager” or “scott/tiger”.  The default Oracle Database policy is to lock accounts thereby restricting access; administrators must consciously grant access to users. Default Authentication in Hadoop By default, a Hadoop cluster fails the authentication test. For example, it is easy for a malicious user to masquerade as any other user on the system.  Consider the following scenario that illustrates how a user can access any data on a Hadoop cluster by masquerading as a more privileged user.  In our scenario, the Hadoop cluster contains sensitive salary information in the file /user/hrdata/salaries.txt.  When logged in as the hr user, you can see the following files.  Notice, we’re using the Hadoop command line utilities for accessing the data: $ hadoop fs -ls /user/hrdataFound 1 items-rw-r--r--   1 oracle supergroup         70 2013-10-31 10:38 /user/hrdata/salaries.txt$ hadoop fs -cat /user/hrdata/salaries.txtTom Brady,11000000Tom Hanks,5000000Bob Smith,250000Oprah,300000000 User DrEvil has access to the cluster – and can see that there is an interesting folder called “hrdata”.  $ hadoop fs -ls /user Found 1 items drwx------   - hr supergroup          0 2013-10-31 10:38 /user/hrdata However, DrEvil cannot view the contents of the folder due to lack of access privileges: $ hadoop fs -ls /user/hrdata ls: Permission denied: user=drevil, access=READ_EXECUTE, inode="/user/hrdata":oracle:supergroup:drwx------ Accessing this data will not be a problem for DrEvil. He knows that the hr user owns the data by looking at the folder’s ACLs. To overcome this challenge, he will simply masquerade as the hr user. On his local machine, he adds the hr user, assigns that user a password, and then accesses the data on the Hadoop cluster: $ sudo useradd hr $ sudo passwd $ su hr $ hadoop fs -cat /user/hrdata/salaries.txt Tom Brady,11000000 Tom Hanks,5000000 Bob Smith,250000 Oprah,300000000 Hadoop has not authenticated the user; it trusts that the identity that has been presented is indeed the hr user. Therefore, sensitive data has been easily compromised. Clearly, the default security policy is inappropriate and dangerous to many organizations storing critical data in HDFS. Big Data Appliance Provides Secure Authentication The BDA provides secure authentication to the Hadoop cluster by default – preventing the type of masquerading described above. It accomplishes this thru Kerberos integration. Figure 1: Kerberos Integration The Key Distribution Center (KDC) is a server that has two components: an authentication server and a ticket granting service. The authentication server validates the identity of the user and service. Once authenticated, a client must request a ticket from the ticket granting service – allowing it to access the BDA’s NameNode, JobTracker, etc. At installation, you simply point the BDA to an external KDC or automatically install a highly available KDC on the BDA itself. Kerberos will then provide strong authentication for not just the end user – but also for important Hadoop services running on the appliance. You can now guarantee that users are who they claim to be – and rogue services (like fake data nodes) are not added to the system. It is common for organizations to want to leverage existing LDAP servers for common user and group management. Kerberos integrates with LDAP servers – allowing the principals and encryption keys to be stored in the common repository. This simplifies the deployment and administration of the secure environment. Authorize Access to Sensitive Data Kerberos-based authentication ensures secure access to the system and the establishment of a trusted identity – a prerequisite for any authorization scheme. Once this identity is established, you need to authorize access to the data. HDFS will authorize access to files using ACLs with the authorization specification applied using classic Linux-style commands like chmod and chown (e.g. hadoop fs -chown oracle:oracle /user/hrdata changes the ownership of the /user/hrdata folder to oracle). Authorization is applied at the user or group level – utilizing group membership found in the Linux environment (i.e. /etc/group) or in the LDAP server. For SQL-based data stores – like Hive and Impala – finer grained access control is required. Access to databases, tables, columns, etc. must be controlled. And, you want to leverage roles to facilitate administration. Apache Sentry is a new project that delivers fine grained access control; both Cloudera and Oracle are the project’s founding members. Sentry satisfies the following three authorization requirements: Secure Authorization:  the ability to control access to data and/or privileges on data for authenticated users. Fine-Grained Authorization:  the ability to give users access to a subset of the data (e.g. column) in a database Role-Based Authorization:  the ability to create/apply template-based privileges based on functional roles. With Sentry, “all”, “select” or “insert” privileges are granted to an object. The descendants of that object automatically inherit that privilege. A collection of privileges across many objects may be aggregated into a role – and users/groups are then assigned that role. This leads to simplified administration of security across the system. Figure 2: Object Hierarchy – granting a privilege on the database object will be inherited by its tables and views. Sentry is currently used by both Hive and Impala – but it is a framework that other data sources can leverage when offering fine-grained authorization. For example, one can expect Sentry to deliver authorization capabilities to Cloudera Search in the near future. Audit Hadoop Cluster Activity Auditing is a critical component to a secure system and is oftentimes required for SOX, PCI and other regulations. The BDA integrates with Oracle Audit Vault and Database Firewall – tracking different types of activity taking place on the cluster: Figure 3: Monitored Hadoop services. At the lowest level, every operation that accesses data in HDFS is captured. The HDFS audit log identifies the user who accessed the file, the time that file was accessed, the type of access (read, write, delete, list, etc.) and whether or not that file access was successful. The other auditing features include: MapReduce:  correlate the MapReduce job that accessed the file Oozie:  describes who ran what as part of a workflow Hive:  captures changes were made to the Hive metadata The audit data is captured in the Audit Vault Server – which integrates audit activity from a variety of sources, adding databases (Oracle, DB2, SQL Server) and operating systems to activity from the BDA. Figure 4: Consolidated audit data across the enterprise.  Once the data is in the Audit Vault server, you can leverage a rich set of prebuilt and custom reports to monitor all the activity in the enterprise. In addition, alerts may be defined to trigger violations of audit policies. Conclusion Security cannot be considered an afterthought in big data deployments. Across most organizations, Hadoop is managing sensitive data that must be protected; it is not simply crunching publicly available information used for search applications. The BDA provides a strong security foundation – ensuring users are only allowed to view authorized data and that data access is audited in a consolidated framework.

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