Ports shown as Interswitch in Policy Manager have detected one of three protocols on the port identified as follows:
- Phones or other devices that use LLDP (Link Layer Discovery Protocol)
- Neighbor switches that use CDP (Cabletron Discovery Protocol); typically Cabletron/Enterasys legacy switches
- Neighbor switches that use EDP (Extreme Discovery Protocol); typically Extreme switches running XoS
If any of these are detected the port will be identified as an Interswitch link indicating that one of these protocols has been detected and the port is not simply an access port with end devices such as a PC or other device that doesn't send out any of these packet types.