ADTRAN AOS Version R10.1.0 Command Reference Manual page 904

Command Reference Guide Global Configuration Mode Command Set
bridge irb
Use the bridge irb command to enable integrated routing and bridging (IRB) and also allow the creation of
bridged virtual interfaces (BVIs). Use the no form of this command to disable the IRB.
Syntax Description
No subcommands.
Default Values
By default, IRB is disabled.
Command History
Release 15.1 Command was introduced.
Functional Notes
The bridge irb must be enabled to create BVIs.
Once the command bridge irb is entered, the IP addresses for any interfaces connected to any bridge will
be removed. Also, the command ip address xx.xx.xx.xx.xx.xx.xx.xx will no longer be available on an
interface that is connected to the bridge.
The BVI must be removed before using the no bridge irb command.
For more information on BVI configuration, refer to the BVI Interface Command Set on page 2042.
Usage Examples
The following example enables IRB:
(config)#bridge irb
Technology Review
The IRB allows the routing of specified protocols between network interfaces and bridge groups. The
difference between IRB and concurrent routing and bridging (CRB) is that in IRB it is possible to route IP
between routed interfaces and BVIs, but with CRB the routed interfaces cannot communicate with bridged
interfaces. IRB's primary goal is to bridge all protocols and route any IP traffic destined for the medium
access control (MAC) address of the BVI.
The IRB handles IP packets in the following manner: When an IP packet comes into the router and it is not
destined for the MAC address, it is bridged. If the IP packet is destined for the MAC address, it is sent to
the routing engine and routed as normal. The IRB allows for PCs in the bridge to get to routed networks
and routed networks to get to the bridge. The bridge group will isolate broadcasts from other routed
interfaces.
A BVI can only be created when IRB is enabled and a bridge group has been defined. The BVI number
corresponds directly to the bridge group.
60000CRG0-35E Copyright © 2012 ADTRAN, Inc. 904