Two NIC cards => Possible to Configure Two Default Routes?

beagle197_at_hotmail.com
Date: 09/26/05 

Date: 26 Sep 2005 08:11:16 -0700

Folks,
I have two DSL providers, can I configure two default routes that are
able to send and receive network packets on both interfaces (eth0 and
eth1) at the same time? It would seem to me that it would be possible,
since if eth0 receives traffic, then response would be sent back
through eth0. The same with eth1. I noted a lot of discussion about
this topic from past posts, where folks have achieved this using
external equipment routers, or that it was possible using Solaris OS. I
am guessing that some Linux folks have devised or written their
customized solution since they went to the extra effort to modify the
TCP/IP stack or tweak the networking kernel modules (but I haven't seen
or heard anything on this point for sure at this time). Is it possible,
and how can I achieve it? I tried to use a higher metric for default
route eth0 verses eth1, but packets were not sent on both interfaces.
Thanks, BEA

bea:/# route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use
Iface
10.0.0.0 0.0.0.0 255.255.255.0 U 0 0 0
eth0
69.109.218.0 0.0.0.0 255.255.248.0 U 0 0 0
eth1
0.0.0.0 69.109.218.1 0.0.0.0 UG 0 0 0
eth1
0.0.0.0 10.0.0.1 0.0.0.0 UG 20 0 0
eth0
bea:/# uname -a
Linux bea 2.6.8-2-686 #1 Thu May 19 17:53:30 JST 2005 i686 GNU/Linux
bea:/# cat /etc/debian_version
testing/unstable
bea:/#

Relevant Pages

  • Re: How to get my 2 ethernet cards to work
    ... interfaces file... ... '/etc/ifplugd/ifplugd.action eth1 up'. ... for eth0. ... please read it before requesting help. ...
    (comp.os.linux.networking)
  • Re: Cant send packets via WiFi (possibly route issue)
    ... which means that the gateway needs a host route. ... > With that you should be able to ping any 192.168.0.x address on ... the only IPs I could ping were IPs of eth0 and eth1. ...
    (comp.os.linux.networking)
  • Re: Proper routes for linux machine with two network ports to same network
    ... I run a Fedora Core 4 system with two network devices eth0 (assigned ... interface is working or sort of, and choose the correct route? ...
    (comp.os.linux.networking)
  • Re: [SLE] Dell True Mobile 1300 on Inspiron 8500 w/SuSE 8.2
    ... First you need to turn off eth0, as I assume you will be using eth1 on the ... same subnet so 2 interfaces with similar IP numbers will confuse. ... and then change in the ifup config file to manual ... Now how is eth1 getting its IP ...
    (SuSE)
  • Configure 2 nics
    ... interfaces in Woody in order to do NAT between them. ... correctly installed and I want to use eth0 in DHCP and eth1 with static ip ... eth1), but not both at the same time. ... workaround is to use the command ifconfig ... ...
    (Debian-User)