Specifications

Terms and Definitions
March 14, 2011 Page 27 of 29
Example
ThefollowingexampleshowsaswitchingdevicewithLoopProtectenabledonportlag.0.2,SID
56:
Enterasys->show spantree lp port lag.0.2 sid 56
LoopProtect is enabled on port lag.0.2, SID 56
Enterasys->show spantree lplock port lag.0.2 sid 56
LoopProtect Lock status for port lag.0.2, SID 56_ is UNLOCKED
Enterasys->show spantree lpcapablepartner port lag.0.2
Link partner of port lag.0.2_is LoopProtect-capable.
Enterasys->show spantree nonforwardingreason port lag.0.2
Port lag.0.2 has been placed in listening or blocking state on SID 0 by the
LoopProtect feature.
Terms and Definitions
Table 9liststermsanddefinitionsusedinSpanningTreeconfiguration.
Display the reason for placing a port in a non-
forwarding state due to an exceptional
condition.
show spantree nonforwardingreason [port
port-string] [sid sid
]
Table 8 Commands for Monitoring Loop Protect (continued)
Task Command
Table 9 Spanning Tree Terms and Definitions
Term Definition
Alternate port Acts as an MSTP alternate path to the root bridge than that provided by the root port.
Backup port Acts as an MSTP backup for the path provided by a designated port toward the
leaves of the Spanning Tree. Backup ports can exist only where two ports are
connected together in a loopback mode or bridge with two or more connections to a
shared LAN segment.
BID Bridge identification, which is derived from the bridge’s MAC address and bridge
priority. The bridge with the lowest BID becomes the root bridge.
BPDU Bridge Protocol Data Unit messages. Used by STP to exchange information,
including designating a bridge for each switched LAN segment, and one root bridge
for the Spanning Tree.
Bridge Switching device.
Bridge priority Assigns the bridge’s relative priority compared to other bridges.
CIST Common and Internal Spanning Tree created by MSTP to represent the connectivity
of the entire network. This is equivalent to the single Spanning Tree used for STP
and RSTP. Communications between MST regions occurs using the CIST.
Designated port A forwarding port within an active topology elected for every switched LAN segment.
Edge port Port on the edge of a bridged LAN.