On Feb 7, 6:26 am, "brother_Matthius" <maciek.ma...@gmail.com> wrote:
> I've seen something like this a few times, mostly on servers with
> HACMP (redundant NICs in failover config).
> For reason I can only guess, AIX routing table redirected outbound
> traffic to 127.0.0.1. Only connection within the same subnet worked
> OK.
>
> Once I disabled PMTU discovery and manually corrected routing table,
> outbound connections started working fine.
> Apparently, PMTU discovery dynamically updates AIX routing table with
> optimized paths to specific hosts - and sometimes makes a mistake.
>
> How to check and disable PMTU discovery:
> no -a | grep pmtu
> grep pmtu /etc/tunables/lastboot
>
> no -p -o udp_pmtu_discover=0
> no -p -o tcp_pmtu_discover=0
>
> no -a | grep pmtu
> grep ptmu /etc/tunables/nextboot
>
> Hope this will help.
>
> Regards,
> brother Matthius

Thanks Bro!

I'll give it a shot, although no HACMP here, but pmtu_discovery was
on.