3Com CoreBuilder 3500, Implementation Manual

Page: 132 / 592

132 C
HAPTER
7: B
RIDGE
-W
IDE AND
B
RIDGE
P
ORT
P
ARAMETERS
Key Guidelines for
Implementation
Consider the following guidelines when you configure bridge-wide and
bridge port parameters on your system:
■
When you disable bridge-wide STP, the bridge cannot participate in
the algorithms for loop detection.
■
Table 13 describes the forwarding behavior of a port based on its
bridge and port STP states:
■
When STP is removed from the port but is enabled for the bridge, the
port is invisible to STP but can forward frames. Removing the port
from STP is useful if you have an edge switch device that is connected
to end stations (such as PCs) that are frequently turned on and off.
■
The port numbering shown for your ports is always sequential. See
Chapter 4 for more information about port numbering.
■
When you are prompted to select ports, specify the
?
option to see a
matrix of information about your bridge ports, including a Selection
column, a Port column, and a Label column.
■
Without trunking, the Selection and Port columns contain the
same port numbers, which indicates that you can select each port.
■
With trunking, the Selection column indicates that you can select
the anchor port (lowest-numbered port) in the trunk, and the Port
column shows each port that is associated with the trunk. The
Label column contains the trunk name, if you have assigned one.
Table 13
Port Forwarding Behavior Depends on Bridge and Port STP States
Bridge STP State Port STP State
Port Participates
in STP? Port Forwards
Frames?
Disabled Disabled No Yes, if link state is up.
Enabled No Yes, if link state is up.
Removed No Yes, if link state is up.
Enabled Disabled No No
Enabled Yes Determined by STP
provided that the port
link state is up.
Removed No Yes, if link state is up.