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Catalyst 3750 SwitchSoftware Configuration Guide
OL-8550-09
Chapter48 Configuring Fallback Bridging
Configuring Fallback Bridging
Beginning in privileged EXEC mode, follow these steps to create a bridge group and to assign an
interface to it. This procedure is required.
To remove a bridge group, use the no bridge bridge-group global configuration command. The no
bridge bridge-group command automatically removes all SVIs and routes ports from that bridge group.
To remove an interface from a bridge group and to remove the bridge group, use the no bridge-group
bridge-group interface configuration command.
This example shows how to create bridge group 10, to specify that the VLAN-bridge STP runs in the
bridge group, to define a port as a routed port, and to assign the port to the bridge group:
Switch(config)# bridge 10 protocol vlan-bridge
Switch(config)# interface gigabitethernet3/0/1
Switch(config-if)# no switchport
Switch(config-if)# no shutdown
Switch(config-if)# bridge-group 10
This example shows how to create bridge group 10 and to specify that the VLAN-bridge STP runs in the
bridge group. It defines an SVI for VLAN 2 and assigns it to the bridge group:
Switch(config)# bridge 10 protocol vlan-bridge
Switch(config)# vlan 2
Switch(config-vlan)# exit
Switch(config)# interface vlan2
Command Purpose
Step1 configure terminal Enter global configuration mode.
Step2 bridge bridge-group protocol
vlan-bridge
Assign a bridge group number, and specify the VLAN-bridge
spanning-tree protocol to run in the bridge group. The ibm and dec
keywords are not supported.
For bridge-group, specify the bridge group number. The range is 1
to 255. You can create up to 32 bridge groups.
Frames are bridged only among interfaces in the same group.
Step3 interface interface-id Specify the interface on which you want to assign the bridge group, and
enter interface configuration mode.
The specified interface must be one of these:
•A routed port: a physical port that you have configured as a Layer3
port by entering the no switchport interface configuration
command.
•An SVI: a VLAN interface that you created by using the interface
vlan vlan-id global configuration command.
Note You can assign an IP address to the routed port or to the SVI,
but it is not required.
Step4 bridge-group bridge-group Assign the interface to the bridge group created in Step 2.
By default, the interface is not assigned to any bridge group. An
interface can be assigned to only one bridge group.
Step5 end Return to privileged EXEC mode.
Step6 show running-config Verify your entries.
Step7 copy running-config startup-config (Optional) Save your entries in the configuration file.