Cisco IOS supported Frame Relay switching (emulation of a Frame Relay switch) for a very long time. First they've implemented local switching, then remote switching over a GRE tunnel. With the introduction of generic Layer 2 transport across a layer-3 backbone (L2TPv3 or AToM), Frame Relay switching got integrated into the new infrastructure, but never implemented completely ... that is, until release 12.0(27)S and 12.4(11)T which finally supports local switching in the new architecture. We've also got a few extra goodies: now you can do DTE-to-DTE switching (interconnecting two Frame Relay switches with a router) or same-port switching (switching two DLCIs terminating on the same router port). The new configuration commands differ only slightly from the old ones. To start with, you have to define DLCIs with the frame-relay interface-dlci switched interface configuration command and use the connect global configuration command to establish switching between two DLCIs. A working example is included below:
frame-relay intf-type dce
frame-relay interface-dlci 100 switched
frame-relay interface-dlci 200 switched
connect FR100_200 Serial0/0/0 100 Serial0/0/1 200
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