Hi,
I observe a strange behavior regarding UDP Reply Packets on multiple WAN interfaces.
Since we have configured a SIP hunting group with our telephone provider, the provider sends option pings on the 3 existing WAN interfaces.
3 DNAT rules are set up, one for each interface.
If the SIP helper on the Sophos XG is switched off, all reply packets are sent via WAN 1. (WAN1 is our primary gateway / no SD WAN policy for this network segment)
If the SIP Helper is enabled on the Sophos XG, all response packets will be answered via the correct interfaces.
SIP Helper switched off:
WAN1 <-> Option Ping / ALL Replies WAN1-3 to SIP Provider
WAN2 <- Option Ping
WAN3 <- Option Ping
SIP Helper switched on:
WAN1 <-> Option Ping / Reply WAN1 to SIP Provider
WAN2 <-> Option Ping / Reply WAN2 to SIP Provider
WAN3 <-> Option Ping / Reply WAN3 to SIP Provider
How can this behavior be explained?
Incorrect configuration?
Best regards Gerd
Added TAGs
[edited by: Raphael Alganes at 3:30 PM (GMT -7) on 16 Apr 2024]