I came across a problem at a customer that I can't seem to solve.
Situation is as follows:
They have two different Internet Lines (two different providers).
One (ISP1) delivers their public wan directly to the barracuda using DHCP
The other (ISP2) has a router in front of our barracuda that does a full DMZ to an internal 192.168.x.x ip that is configured on the barracuda and the barracuda handles it from there.
We have configured source based routing for the network so the barracuda can determine how to route traffic and everything is working (surfing over ISP1 Fallback over ISP2) and the rules are also working nicely.
Incoming SMTP traffic.
They can accept mailtraffic from the entire world except their DHCP public wan range. Mail coming from that range (it is a /19 range) the rule gives a Reverse Routing Interface Mismatch error.
The kicker is, the incoming mails are incoming from ISP2.
I have tried enabling tcp raw mode.
Creating a rule to route the traffic over the ISP1 route ...
with no success.
Interface mismatch keeps happening.
As it stands I asked the customer to let me change their MX record so the ISP1 WAN IP is the primary MX.
But this is not the ideal solution.
anyone has any ideas how to solve this?