Visit Jeremy's Blog.
Go Back > Forums > Linux Forums > Linux - Newbie
User Name
Linux - Newbie This Linux forum is for members that are new to Linux.
Just starting out and have a question? If it is not in the man pages or the how-to's this is the place!


  Search this Thread
Old 02-12-2009, 09:24 AM   #1
LQ Newbie
Registered: Feb 2009
Posts: 1

Rep: Reputation: 0
Exclamation multihomed nic's in ubuntu 8.10

Hi All,

I am just getting to grips with ubuntu after years of solaris. So please be patient with the newbie questions.

I have a server with 2 nic's I have no firewall enabled as yet.

my /etc/network/interfaces contains the following

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0 eth1

iface eth0 inet static
# dns-* options are implemented by the resolvconf package, if installed

iface eth1 inet static

the default gateway needs to be as thats where all the traffic needs to go. (internet facing)

now when i try to connect to the it doesnt connect me, the packets are supposed to come in on eth1 and out on eth0
a tcp dump does shows on eth1 mypc -> eth1, however on eth0 i see no packet leaving the system at all.

ip route get shows the default gateway being which is correct.

Is there a setting that is blocking return packets with a src address not being the interface that the packet is leaving from.

or am i missing something more fundemental.

This behaviour works out of the box on the solaris boxes we are replacing with ubuntu.

Thanks in advance for any light that can be shed on this


Tony Mills
Old 02-13-2009, 05:49 PM   #2
Senior Member
Registered: Feb 2002
Location: harvard, il
Distribution: Ubuntu 11.4,DD-WRT micro plus ssh,lfs-6.6,Fedora 15,Fedora 16
Posts: 3,233

Rep: Reputation: 406Reputation: 406Reputation: 406Reputation: 406Reputation: 406
hmm, correct me if im wrong but you are trying to configure the machine to route traffic requests from internal network eth1 to internet facing interface eth0? such as you have a lan plugged into eth1 and your internet connection on eth0?
there is a gui called firestarter
that might help


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Multihomed system troubles rven Linux - Networking 1 01-12-2009 05:01 PM
Using IPTABLES on Multihomed Box SBN Linux - Security 4 10-12-2007 07:48 PM
I have two ubuntu boxes, a dell with two nic's and an emachine, can not network them. bradshoults Linux - Networking 6 08-13-2007 12:18 AM
UDP Response with a Multihomed NIC shinepuppy Linux - Networking 0 11-01-2006 08:53 AM
Which wireless NIC's does Linux (ubuntu) support best? nickk Linux - Hardware 2 09-06-2006 12:08 AM > Forums > Linux Forums > Linux - Newbie

All times are GMT -5. The time now is 11:44 PM.

Main Menu
Write for LQ is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Open Source Consulting | Domain Registration