[CentOS] Two external interfaces, one with "default" route and ping problem

Tue Aug 20 03:41:54 UTC 2013
Jobst Schmalenbach <jobst at barrett.com.au>


I have two different IP addresses (in a block of /29), one is on port 0 and the other is on port 2 of a Ciso 888.
I am doing this so I can have two different certs with two different ip addresses.

I have tried:

 1) one machine, two real interfaces, two cables (eth0 and eth2)
 2) one machine, one real interface eth0 and one virtual interface eth0:1, one network cable

Using number 2)
I can ping the two different ip addresses, no problem. The only problem here is that iptables does not work (I cannot create rules for eth0:1 - and yes I know about the security implications).

I have a problem with number number 1)

I can ping the first ip address and I get a return, but I cannot get a return when I ping the second ip address.
I can see traffic coming into the second interface but it does not return.
Now one of the interfaces needs the "default" route applied (is this correct??), which is eth0.

I assume this is a routing problem?
What do I need to do to get this to work?


Student to Teacher: Sir, what's an oxymoron? .... Teacher to Student: "Microsoft Works".

  | |0| |   Jobst Schmalenbach, jobst at barrett.com.au, General Manager
  | | |0|   Barrett Consulting Group P/L & The Meditation Room P/L
  |0|0|0|   +61 3 9532 7677, POBox 277, Caulfield South, 3162, Australia