[OpenSIPS-Users] Opensips relaying MESSAGE - source IP problem

[Sebastien CRUAUX]

Hi,

I'm encountering some issue with my Opensips configuration.
My Opensips server is configured to relay SIP MESSAGE requests to 
another server when the destination URI is not located on my server. 
Here is the part of opensips.cfg which is concerned :

if (!lookup("location","m")) {

   switch ($retcode) {
     case -1:
     case -3:
       rewritehost("10.254.230.148");
       if (is_method("MESSAGE")) {
     rewriteport("5062");
       }
       if (!t_relay()) {
     sl_reply_error();
       } exit;
     case -2:
       sl_send_reply("405", "Method Not Allowed");
       exit;
   }
}

My server receives SIP requests on eth0 interface (IP 10.254.31.45) but 
when it relays the requests to the server 10.254.230.148 it should use 
eth2 IP (10.254.28.45) as src IP because there is a firewall between the 
two servers and port 5062 is only allowed for source IP 10.254.28.45. 
The problem is the following : when I open Wireshark on my Opensips 
server, I can see that the source IP for the relayed MESSAGE is still 
10.254.31.45 so it never reaches the other server ! I don't understand 
where is the issue, my Linux routing table is OK, when I'm trying to 
reach 10.254.230.148 from my Opensips server using telnet for example it 
uses the right interface and the right gateway. Here is my routing table :

10.254.230.144 10.254.28.1 255.255.255.240 UG 0 0 0 eth2
10.254.31.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
10.254.28.0 0.0.0.0 255.255.255.0 U 0 0 0 eth2
10.254.29.0 0.0.0.0 255.255.255.0 U 0 0 0 eth3
192.168.0.0 10.254.28.1 255.255.255.0 UG 0 0 0 eth2
10.254.225.0 10.254.28.1 255.255.255.0 UG 0 0 0 eth2
0.0.0.0 10.254.31.1 0.0.0.0 UG 0 0 0 eth0

Did I miss something in Opensips configuration file ?
Thanks a lot for your help.

Best Regards,

Sebastien