Hi,

I have a linux system (suse linux) with two nic. when i configured it i was getting the outgoing adress from my machine of 1st nic as a source address but now when i request outside it shows the ip address of second nic as a source address. But i want it should be 1st nic. How can i do that.

thanks in advance


Ramchandra

Not sure I fully understand you, let me see if I get this straight and I will see what I can do to help.

This is what I understand:

You have a machine with 2 network cards you are hoping to setup as some form of gateway/router.
NIC1 should be your inernet facing nic.
NIC2 should be your LAN (private network) facing nic.
When you first set it up and established an internet connection, the outbound packets showed NIC1 as their source address.
Now, for some reason, when you establish an outbound internet connection, the source addresses on those packets is the address of NIC2.

Ok, let me know if that's correct. If it is I have a couple questions:

1) Have you switched your cables around at all? You might have swapped them if they were not properly labelled, although doing so should have given you some network problems (wrong IPs etc... unless you're using DHCP for both NICs)

2) Where are you sniffing the packets from? Do you have another machine between this one and the internet? Between this one and the LAN? Or are you sniffing on this machine itself? Depending on where you are in the routing process you are going to get different results, especially if it's a packet being routed through your machine and not originating there...