6-2
Ethernet Card Software Feature and Configuration Guide, R7.2
January 2009
Chapter 6 Configuring Bridges
Configuring Basic Bridging
Spanning tree is not mandatory for an ML-Series card bridge group. But if it is configured, a
separate spanning-tree process runs for each configured bridge g roup. A bridge group
establishes a spanning tree based on the bridge protocol data units (BPDUs) it re ceives on only
its member interfaces.
Configuring Basic Bridging
Use the following steps to configure bridging:
Figure 6-1 shows a bridging example. Example 6-1 shows the configuration of ML-Series card A.
Example 6-2 shows the configuration of ML-Series card B.
Command Purpose
Step 1 Router(config)# no ip routing Enables bridging of IP packets. This command needs to be
executed once per card, not once per bridge-group. This step is
not done for integrated routing and bridging (IRB).
Step 2 Router(config)# bridge
bridge-group-number
[protocol
{drpi-rstp | rstp | ieee}]
Assigns a bridge group number and defines the appropriate
spanning-tree type:
bridge-group-number can range from 1 to 4096.
drpri-rstp is the protocol used to interconnect dual RPR
interconnect to protect from node failure
rstp is the IEEE 802.1W Rapid Spanning Tree.
ieee is the IEEE 802.1D Spanning Tree Protocol.
Note Spanning tree is not mandatory for an ML-Series card
bridge group. But configuring spanning tree blocks
network loops.
Step 3 Router(config)# bridge
bridge-group-number
priority
number
(Optional) Assigns a specific priority to the bridge, to assist in
the spanning-tree root definition. Lowering the priority of a
bridge makes it more likely the bridge is selected as the root.
Step 4 Router(config)# interface
type
number
Enters interface configuration mode to configure the interface of
the ML-Series card.
Step 5 Router(config-if)# bridge-group
bridge-group-number
Assigns a network interface to a bridge group.
Step 6 Router(config-if)# no shutdown Changes the shutdown state to up and enables the interface.
Step 7 Router(config-if)# end Returns to privileged EXEC mode.
Step 8 Router# copy running-config
startup-config
(Optional) Saves your entries in the configuration file.