Bridge¶

Bridge allows the connection of two separate networks as if they were a single network. It builds a database by inspecting the destination MAC address of packets flowing through the bridged interfaces: known destination is forwarded, unknown is broadcast to all other networks.

To configure a bridge, enter the context interface type bridge from the VRF in which you plan to define the bridge logical interface. The bridge configuration is valid as soon as the slave interfaces are set.

Here is an example of bridge named br0 in VRF main, using two interfaces eth0 and eth1.

vsr running vrf main# interface bridge br0
vsr running bridge br0# link-interface eth0
vsr running bridge br0# link-interface eth1
vsr running bridge br0# commit

The bridge interface is configured provided eth0 and eth1 are present in VRF main.

Let’s fetch the state after committing this configuration:

vsr running vrf main# interface bridge br0
vsr running bridge br0# show state
bridge br0
    oper-status UNKNOWN
    enabled true
    mtu 1500
    link-interface eth0
    link-interface eth1
    ethernet
        mac-address 9a:cb:9c:2e:fd:07
        ..
    counters
        in-octets 0
        out-octets 0
        in-errors 0
        in-unicast-pkts 0
        in-discards 0
        out-unicast-pkts 7
        out-errors 0
        out-discards 0
        ..
    ipv6
        address fe80::98cb:9cff:fe2e:fd07/64
        ..
    ..

The same configuration can be made using this NETCONF XML configuration:

vsr running config# show config xml absolute vrf main interface bridge br0
<config xmlns="urn:6wind:vrouter">
  <vrf>
    <name>main</name>
    <interface xmlns="urn:6wind:vrouter/interface">
      <bridge xmlns="urn:6wind:vrouter/bridge">
        <name>br0</name>
        <enabled>true</enabled>
        (...)
        <link-interface>
          <slave>eth0</slave>
        </link-interface>
        <link-interface>
          <slave>eth1</slave>
        </link-interface>
      </bridge>
    </interface>
  </vrf>
</config>

Forwarding Database¶

The bridge interfaces store in a table which MAC addresses have been learned and from which port they came from. This is called the forwarding database or FDB.

The bridge FDB can be observed with the show bridge fdb command.

vsr> show bridge fdb name br0
interface link-layer-address link-interface state
========= ================== ============== =====
br0       de:ed:02:44:51:1b  eth1           permanent
br0       de:ed:01:2c:d8:2b  eth0           permanent
br0       de:ed:02:94:ea:3b  eth1           reachable