RSPAN causes port to go into BKN state due to PVID inconsistency 
Bug ID:
CSCtj76880
Resolved In:
12.2(58)SE; 12.2(55)SE3; 15.0(4.1)SID;
Symptom:
Port goes into spanning tree inconsistent ( BKN ) state due to PVID inconsistency.
Conditions:
RSPAN configured to monitor a vlan. Both the RSPAN vlan and the monitored vlan
passes over the trunk. Issue not seen when the VLAN is not set for remote-span
Affected platform list
WS-C2960, WS-C2960G
WS-C3560, WS-C3560G
WS-C3750, WS-C3750G
ME-2400, ME-3400, ME-3750
WC-CBS30x0, IE-3000
Workaround:
Change trunk encapsulation from dot1Q to ISL.
Solution:
Implement workaround or upgrade IOS to a resolved IOS version.
NOTE: Due to the simplicity of this workaround, it is highly recommened instead of an IOS upgrade because of IOS vulnerability CSCto62631 which caused 12.2(58)SE to be deferred and lack of support from 12.2(58)SE1 for a number of switching platforms i.e. http://bit.ly/xA8Mhd.
Type: Bug - Archive ID: 1.15559 - 136 Views - Last Updated: February 16, 2012 16:04:12
Tags: Cisco Software IOS; RSPAN STP bug 12.2(55)SE dot1Q ISL CSCto62631 RSPAN