Calls sent to non primary IP address are replied back only from primary IP address

[Hawkeye]

Hi,
Have a few IP addresses configured on one NIC. Carrier sends calls to separate IP addresses for a variety of reasons. The issue is, the reply back from the pbx server is only sent from the primary ip address configured on the nic.

example:
Primary IP address: x.x.x.100
Secondary IP address: x.x.x.101
Tertiary IP address: x.x.x.110

Carrier sends calls to .110 but server replies back from .100. Is there any way to get the pbx to send back replies to carrier from the IP address the call was sent to?

Thanks.

[billsimon]

Setting a static route in Linux should cause the server to reply from the IP you want.

[cynjut (Dave Burgess)]

@billsimon

Setting a static route in Linux

To amplify - this isn’t a PBX question, per se; it’s a Linux question. Now, there are some PBX parts to it. For example, the SIP driver is bound to a single address per PBX instance, so you may be able to send the packets back out on the “right” interface, but the SIP traffic may well have the single “outgoing” address in the SIP headers, thwarting the goodness you are looking for.

It sounds to me like you are trying to do something that FreePBX may not be happy trying to do. Can you explain your use-case a little bit; perhaps we (as a community) can provide an alternate solution or two…

[billsimon]

@cynjut

so you may be able to send the packets back out on the “right” interface, but the SIP traffic may well have the single “outgoing” address in the SIP headers, thwarting the goodness you are looking for.

I thought about this too, but if he uses PJSIP bound to 0.0.0.0 I was thinking it might work. Testing needed!