Jail is able to ping multiple networks. Why?

[dirtyb15]

Hello all. My TrueNAS server has two NICS. Each is used by a separate network. (One is in the 192.168.1.x range, the other 10.42.0.x range). I have a jail set up as a dns server and it is set to use one interface, and has a static ip as 192.168.1.10. The other day i noticed one of the machines on the 10.42.0.x network was set to DHCP, and was being assigned a 192.161.1.x address. From the jail console, i am able to ping all of the machines on both networks even though it has a static ip and mask of 255.255.255.0. How to isolate this jail to just the one network? Thanks for any help!