Force ITSP registration to 2nd NIC

Looking for some advice to this one. Have a server with 2 NICS in it and need to force the sip trunk registrations with Vitelity on the 2nd NIC. Any help would be appreciated, thanks.

Presumably the NIC’s are in different networks, Regular Linux routing should take care of that

ip route add 64.2.142.0/24 via 10.10.10.3 dev eth1

where 10.10.10.3 is the gateway on the network eth1 is connected to, and 64.2.142.0/24 is the vitelity inbound servers network.

is this done in the freepbx gui or in a conf file?

Neither, it is a generic instruction to iproute2 to add a route to your layer 3 stack. It was you that added a second NIC card, you will need acustomise yourself to how that will impact your network and further the setup would be OS specific, but you could add it to /etc/rc.local if you want to.