FIB (routing table) question with jailed service

Hello,

I set up a second routingtable and told rc.d/jail to use the FIB1.
Now I wonder why the SSHd in the jail isn't responding. I set the
default router to a local address and the second default router in FIB1
to the ISP router, reachable via a second NIC.
Does the FIb only work for outgoing, intiating connections?

Best regards,

-Harry