Use the Command Reference to Check Your Memory
Table 3-3 lists the important commands from this chapter. To test your memory, cover the right side of the table with a piece of paper, read the description on the left side, and see how much of the command you can remember.
Table 3-3 Command Reference
Task |
Command Syntax |
Configure the STP priority for a switch so that it is a root bridge or a backup root bridge |
spanning-tree vlan vlan-id root {primary | secondary} [diameter diameter] OR spanning-tree vlan vlan-id priority priority |
Configure the STP port cost |
spanning tree [vlan vlan-id] cost cost |
Configure the STP port priority on the downstream port |
spanning-tree [vlan vlan-id] port-priority priority |
Enable root guard on an interface |
spanning-tree guard root |
Enable STP portfast globally, for a specific port, or for a trunk port |
spanning-tree portfast default OR spanning-tree portfast OR spanning-tree portfast trunk |
Enable BPDU guard globally or for a specific switch port |
spanning-tree portfast bpduguard default OR spanning-tree bpduguard {enable | disable} |
Enable BPDU guard globally or for a specific interface |
spanning-tree portfast bpdufilter default OR spanning-tree bpdufilter enable |
Enable STP loop guard globally or for a specific interface |
spanning-tree loopguard default OR spanning-tree guard loop |
Enable automatic error recovery for BPDU guard. |
errdisable recovery cause bpduguard |
Change the automatic error recovery time |
errdisable recovery interval time-seconds |
Enable UDLD globally or for a specific port |
udld enable [aggressive] OR udld port [aggressive] |
Display the list of STP ports in an inconsistent state |
show spanning-tree inconsistentports |
Display the list of neighbor devices running UDLD |
show udld neighbors |