[Baylisa] DSR load balancer oddities with Ubuntu?

Fri May 10 13:07:21 PDT 2013

# Controls source route verification

net.ipv4.conf.default.rp_filter = 0

That is the one  was talking about.

From: Anton Cohen [mailto:anton at antoncohen.com] 
Sent: Friday, May 10, 2013 12:54
To: Ulf Zimmermann
Cc: Ray Wong; baylisa at baylisa.org
Subject: Re: [Baylisa] DSR load balancer oddities with Ubuntu?

On Fri, May 10, 2013 at 12:24 PM, Ulf Zimmermann <ulf at alameda.net> wrote:

Newer Linux kernel have a setting to disallow that. I am not at a computer
to look up the sysctl variable but look for something starting with rt or
rp.

On May 10, 2013, at 12:12, Ray Wong <rayw at rayw.net> wrote:

> Well, it sort of has to with DSR, right? :) the traffic hits the BigIP,
forwards to the server, and the server replies directly out the router. I'm
probably being thickheaded from a long week, do you mean some other sort of
pathing?

I think Ulf is right, expect the other way around. You need different return
paths and Ubuntu disables them by default [1]. Try disabling return path
filtering [2].

[1] https://bugs.launchpad.net/ubuntu/+source/procps/+bug/201952

[2] http://serverfault.com/a/35769/148146