From: Sadiq Yakasai (sadiqtanko@gmail.com)
Date: Mon Feb 11 2008 - 13:04:10 ARST
Hi Thomas,
On any given segment of a network, one port has to be the in the
forwarding state and the switch with a port in the forwarding state
for that same segment will be the designated bridge.
Even when ports are in blocking state, they still listen to BPDU's on
that blocking port. This is how switches learn about indirect link
failures (spanning-tree backbone fast feature uses this concept) by
receiving superior BPDUs on a blocking port, amongst a few other
stuff.
When a switch has a port in the blocking state, and it stops receiving
BPDU's on the same port, for the period of the MaxAge timer, then it
assumes the designated bridge on that segment is dead and it
recalculates STP accordingly.
HTH
Sadiq
#19963
This archive was generated by hypermail 2.1.4 : Sat Mar 01 2008 - 16:54:48 ARST