ICE not working with multiple interfaces

[neeraj.p@xxxxxxxxxxx (neeraj.p)]

Hey 

I am using PJSIP on two machines . Both the machines have two active network interfaces.
Clients are making stun request (for UDP hole punching) to both the interfaces .
But they are generating stun response from a single ip address. 
What could be the reason for this behavior .

Please help.

Regard,
neeraj