VLAN Routing. Virtual LAN (VLAN) support on the NM-1FE-TX module enables network managers togroup users logically rather than by physical location, easing adds, moves, and changes. VLAN traffic can be transported using Cisco's ISL protocol for communication with the Catalyst 5000, 5500, and 3000 switches. Routing is possible between VLANs in Cisco switches such as the Catalyst 5000, 5500, Catalyst 3000 series, and the Catalyst 1900 and 2820 series switches.