Basic Bridge Networking

This is an example of how to set up a VLAN transparent bridge with a DHCP assigned IP address. We have a system with two interfaces, or ports, named eth0 and eth1.

Figure 1: eth0 faces the office LAN, eth1 a PC. Both become ports of br0, which picks up a management address over DHCP.

admin@example:/> show interface
⚑ INTERFACE       PROTOCOL      STATE       DATA
  lo              loopback      UP
                  ipv4                      127.0.0.1/8 (static)
                  ipv6                      ::1/128 (static)
  eth0            1000baseT     UP          duplex: full
                  ethernet                  00:c0:ff:ee:00:01
                  ipv6                      fe80::2c0:ffff:feee:1/64 (link-layer)
  eth1            1000baseT     UP          duplex: full
                  ethernet                  00:c0:ff:ee:00:02
                  ipv6                      fe80::2c0:ffff:feee:2/64 (link-layer)

Each interface is listed as a stack of protocol rows. For a port with link, the top row names the IEEE PMD type and the negotiated duplex, with the MAC address on the ethernet row below it.

Creating a bridge and setting our interfaces as bridge ports is a straight forward operation.

admin@example:/> configure
admin@example:/config/> set interface br0
admin@example:/config/> set interface eth0 bridge-port bridge br0
admin@example:/config/> set interface eth1 bridge-port bridge br0

Because it does not make much sense to have IP addresses on bridge ports, Infix takes care to disable IPv6 SLAAC on them automatically when we attach interfaces to a bridge.

We can use the diff command to inspect the changes. Notice how the system has automatically set the bridge interface type for us. This is a feature of the CLI and not available over NETCONF or RESTCONF.

admin@example:/config/> diff
interfaces {
+  interface br0 {
+    type bridge;
+  }
  interface eth0 {
+    bridge-port {
+      bridge br0;
+    }
  }
  interface eth1 {
+    bridge-port {
+      bridge br0;
+    }
  }
}

Now we enable a DHCP client on br0 and activate the changes.

admin@example:/config/> edit interface br0
admin@example:/config/interface/br0/> set ipv4 dhcp
admin@example:/config/interface/br0/> leave
admin@example:/>

Back in admin-exec mode we inspect the changes and notice the bridge has already got a DHCP lease from the server.

admin@example:/> show interface
⚑ INTERFACE       PROTOCOL      STATE       DATA
  lo              loopback      UP
                  ipv4                      127.0.0.1/8 (static)
                  ipv6                      ::1/128 (static)
  br0             bridge
  │               ethernet                  00:c0:ff:ee:00:01
  │               ipv4                      192.168.1.161/24 (dhcp)
  │               ipv6                      fe80::2c0:ffff:feee:1/64 (link-layer)
  ├ eth0          bridge        FORWARDING
  └ eth1          bridge        FORWARDING

admin@example:/>

The ports are now listed beneath br0, each in the FORWARDING state, and the addresses have moved from the ports to the bridge.

Remember to save your changes for next boot:

admin@example:/> copy running-config startup-config

For more information about networking in Infix, see the official documentation.