[afnog] Packet Forwarding Issue with Linux

[Hugo Lombard]

On Mon, Apr 11, 2011 at 10:50:23AM +0300, Gerald Begumisa wrote:
>    On Mon, Apr 11, 2011 at 10:09 AM, Hugo Lombard <[1]hal at elizium.za.net>
>    wrote:
> 
>       /sbin/sysctl net.ipv4.ip_forward
> 
>    # sysctl net.ipv4.ip_forward
>    net.ipv4.ip_forward = 1
> 

Expected as much, since without it the packet wouldn't have been
forwarded on the outbound leg, but good to be sure :)

The routing table looks fine.

There's only two things that come to mind:

- reverse path filtering

This should be unlikely, because the routing table looks OK.  But just
for that extra bit of certainty, turn off rp_filter for eth2 
(/sbin/sysctl -w net.ipv4.conf.eth2.rp_filter=0) and see if that makes
any difference?

- TTL expiry

A long shot too, but what is the TTL on ping reply packets coming in on
eth2?


Then, just to double check:  You don't see any ping reply packets
exiting eth0 on the "router" server?

Does eth0 and eth2 connect to two different switches?

-- 
Hugo Lombard