[Users] OpenVZ on EL6 - weird network issue

[Michael Stauber]

Hi Scott,

> [...] almost always it was inside of a commercial datacenter. 

Yeah, it's in a large datacenter as well.

> The cause of the problem seemed to be some upstream routing
> device that was periodically dropping ARP table entries for
> the containers.

That is indeed interesting. Well, I guess there is only one way to find
out. I'll set up a cronjob as suggested to do periodic arpseeds. It sure
won't hurt.

So far we tried this here:

http://forum.proxmox.com/threads/8301-OpenVZ-Containers-lose-internet-connection-%28VLAN-venet%29

TL;DR:

echo 2 > /proc/sys/net/ipv4/conf/br0/rp_filter

That sounded good on paper, but just 20 hours later we had the next outage.

The OpenVZ wiki also pointed out this here ("Bridge doesn't forward
packets"):

http://openvz.org/Bridge_doesn%27t_forward_packets

Yet I'm not sure how applicable that might be to us. I noted down the
current status of /proc/sys/net/bridge/* and will compare it with what
it'll be during the next loss of connectivity.

> I'd like to hear more once you get it figured out.

Sure, I'll post follow ups then. Likewise: If you have any other ideas
or suggestions, then I'd love to hear them.

-- 
With best regards

Michael Stauber