[Baylisa] DSR load balancer oddities with Ubuntu?

[Ray Wong]

Hey, I know the list has been quiet on tech discussions lately, but I'm
hoping someone can help as my google-fu is not strong on this, it seems.

We've been trying to migrate some of our old Fedora Core machines to Ubuntu
(12.04LTS), and have run into an annoying difference in network behavior,
which I'm hoping someone else has encountered and figured out a fix.

We split our CIDR allocation, and backhaul our office bandwidth through the
colo a couple blocks away. The load balanced network and the office are
routed and separate blocks/masks/vlans, but for some reason office traffic
can't seem to talk to Ubuntu servers using DSR behind an F5 BigIP. The FC
machines work fine, it's only Ubuntu that doesn't seem able to do this, and
it works from anywhere outside. I'm using the dummy interface for the VIPs
with the arp_ignore set to 1 and arp_announce set to 2, which seems to have
everything working except for this one strange issue.

Anyone else doing this successfully?