Multi-homed server with 1 static IP and 1 floating IP (like VRRP) having audio issues

Hey Folks,

We’re transitioning a server from a static IP to a “floating” IP which we can switch over to a hot-spare should the primary server fail. This would negate the need to change settings on devices and trunk providers in the event of a failure.

For this example, lets say is the old IP, and is the new IP. Default GW is

The problems I see:

P1 - the handsets fail to register on the new IP address as “reply” traffic is bound to the old IP.
A1 - I can work around this with a static route ip route add <handset ip>/32 via dev eth0 src This essentially forces a source IP for that specific hand-set, which then is able to register, but then I have 1-way or none audio issues.

P2 - I have the old IP defined in the SIP settings as most traffic is still live and we have some devices behind NAT - This might be what’s causing the audio failure above as RTP is trying to use the wrong IP on the server.

Any help and suggestions on how to work this out is greatly appreciated.


After extensive digging, this appears to be a “by design” issue with the SIP code.
I was not able to solve the problem and have redesigned around it.