Configuring Layer 2 Bridging Interfaces
Integrated routing and bridging interfaces are logical Layer 3 VLAN interfaces that route traffic between bridge domains (VLANs). So, an IRB logical interface is usually associated with a bridge domain or VLAN. The IRB logical interface also functions as the gateway IP address for the other devices on the same sub-network that are associated with the same VLAN. IRB interfaces support Layer 2 bridging and Layer 3 routing on the same interface. As a result, IRB interfaces enable the router to act both as a router and as a Layer 2 switch at the same time.
If the status of all Layer 2 logical interfaces in the bridge domain is down, the status of the irb logical interface is also down.
To configure an IRB logical interface:
- In configuration mode, at the [edit bridge-domains] hierarchy level, configure the bridge domain by specifying the
name of the bridge and the VLAN ID.[edit bridge-domains]user@host# set bridge-domain-name vlan-id vlan-id
- Configure an interface in trunk mode and include the interface
in the appropriate bridge domain using the vlan-id-list command at the [edit interfaces] hierarchy level.[edit interfaces]user@host# set interfacetype-fpc/pic/port vlan-tagginguser@host# set interfacetype-fpc/pic/port unit logical-unit-number family bridge interface-mode trunkuser@host# set interfacetype-fpc/pic/port unit logical-unit-number family bridge vlan-id-list vlan-id
- Configure the IRB interface at the [edit interfaces] hierarchy level and specify the associated IP address.[edit interfaces]user@host# set interfaces irb unit logical-unit-number family inet address address
- Configure the IRB interface as the routing interface for
the bridge domain at the [edit bridge-domains] hierarchy
level.[edit bridge-domains]user@host# set bridge-domain- name vlan-id vlan-id routing-interface irb.logical-interface-number