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Catalyst 3550 Multilayer Switch Software Configuration Guide
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Chapter 26 Configuring Fallback Bridging
Configuring Fallback Bridging
Beginning in privileged EXEC mode, follow these steps to filter by the MAC-layer address:
To disable the frame forwarding ability, use the no bridge bridge-group address mac-address global
configuration command.
This example shows how to forward a frame with MAC address 0800.cb00.45e9 through an interface in
bridge group 1:
Switch(config)# bridge 1 address 0800.cb00.45e9 forward gigabitethernet0/1
Adjusting Spanning-Tree Parameters
You might need to adjust certain spanning-tree parameters if the default values are not suitable for your
switch configuration. Parameters affecting the entire spanning tree are configured with variations of the
bridge global configuration command. Interface-specific parameters are configured with variations of
the bridge-group interface configuration command.
You can adjust spanning-tree parameters by performing any of the tasks in these sections:
• Changing the Switch Priority, page 26-8
• Changing the Interface Priority, page 26-8
• Assigning a Path Cost, page 26-9
• Adjusting BPDU Intervals, page 26-10
• Disabling the Spanning Tree on an Interface, page 26-12
Note Only network administrators with a good understanding of how switches and STP function should
make adjustments to spanning-tree parameters. Poorly planned adjustments can have a negative
impact on performance. A good source on switching is the IEEE 802.1d specification; for more
information, refer to the “References and Recommended Reading” appendix in the Cisco IOS
Configuration Fundamentals Command Reference.
Command Purpose
Step 1
configure terminal Enter global configuration mode.
Step 2
bridge bridge-group address mac-address
{forward | discard} [interface-id]
Specify the MAC address to discard or forward.
• For bridge-group, specify the bridge group number. The range is 1
to 255.
• For address mac-address, specify the MAC-layer destination
address to be filtered.
• Specify forward if you want the frame destined to the specified
interface to be forwarded. Specify discard if you want the frame to
be discarded.
• (Optional) For interface-id, specify the interface on which the
address can be reached.
Step 3
end Return to privileged EXEC mode.
Step 4
show running-config Verify your entry.
Step 5
copy running-config startup-config (Optional) Save your entry in the configuration file.
