route traffic out to internet

Were you a version 4.x user? I ask only because in version 4.x, there was a checkbox to enable routing, whereas in version 9.x, there isn't, and as such, the F5 became a default deny platform at layer3. In order to enable the routing outbound, particularly if the F5 is inline to your outbound traffic, you'll need to create a network virtual server to do this. I would make sure you only enable this on your internal vlan:

virtual default-forwarder {
   destination any:any
   ip forward
   profile fastL4
   vlans DMZb enable
}