Product guide

Spanning-Tree Operation
Overview
Note for 802.1D
and 802.1w
Spanning-Tree
Operation for
the Series
5300xl and
Series 3400/
6400cl switches
You should enable spanning tree operation in any switch that is part of a
redundant physical link (loop topology). (HP recommends that you do so on
all switches belonging to a loop topology.) This topic is covered in more detail
under “How STP and RSTP Operate on the 5300xl, 3400cl and 6400cl Switches”
on page 6-8.
As recommended in the IEEE 802.1Q VLAN standard, the switches covered
by this guide use single-instance STP for 802.1D and 802.1w spanning-tree
operation. (In this case, the switch generates untagged Bridge Protocol Data
Units—BPDUs.) This implementation creates a single spanning tree to make
sure there are no network loops associated with any of the connections to the
switch, regardless of whether multiple VLANs are configured on the switch.
Thus, when using 802.1D or 802.1w spanning tree, these switches do not
distinguish between VLANs when identifying redundant physical links. In this
case, if VLANs are configured on the switch, see “RSTP and STP Operation
with 802.1Q VLANs” on page 6-9.
6-6