stp

[dkblee]

hi! When i run the "sh spanning-tree" command, there's a column "Type : P2P peer (STP)" what does that mean?

if one of the interface of the the switch that's connected to another switch is in "altn" role, what would be the role and stat of the port on the end of the switch?

Please advise. Thanks.

[Francois Tallet]

It means that the neighbor is running STP (legacy STP vs RSTP/MST) and that your local STP considers the port as point-to-point. Point-to-point is an important parameter for RSTP and MST because it allows a designated port to negotiate going to forwarding immediately with a direct neighbor also running RSTP or MST.

If a port is alternate, the neighbor (if it is unique) should be designated.

HTH,

Francois

[cisco_lad2004]

1-Alternate port?offers an alternate path toward the root switch to that provided by the current root port.

2-P2P peer indicates a connection to another switch.

HTH

Sam

http://cisco.com/en/US/docs/switches/lan/catalyst3550/software/release/12.1_12c_ea1/configuration/guide/swmstp.html