EdgeRouter - How do I convert an EdgeRouter Lite 1WAN+2LAN to 1WAN+1LAN (eth0 and eth2 bridged)?

Overview


Readers will learn how to convert an EdgeRouter-Lite configured with the 1WAN+2LAN Wizard to 1WAN+1LAN (eth0 and eth2 bridged)

Generally, we do not recommend bridging ports on routers, as it will reduce the overall throughput compared to non-bridged configurations.  If you require more than 1 LAN port on the same layer 2 network, we strongly advise using a switch as it is the right tool for the job.  That being said, bridging may be acceptable in some environments.  (Note: The EdgeRouter-POE has three ports on a switch chip. If you only need three ports on the same LAN, that unit might be a better fit)

The following assumes your ER-Lite has been configured using the 1WAN+2LAN Wizard and you are connected via SSH on eth0 (192.168.1.1)

Commands


We need to remove the IP address from eth2

configure
delete interfaces ethernet eth2 address 192.168.2.1/24
commit

Now we create a new bridge interface, assign an IP address and add eth2 to the bridge-group

set interfaces bridge br0
set interfaces bridge br0 address 192.168.2.1/24
set interfaces ethernet eth2 bridge-group bridge br0
commit
save
exit

 

Now plug into eth2 and either give yourself a static IP like 192.168.2.2 or set your computer to obtain an address automatically (DHCP).  Here we are removing the IP address from eth0.  (Note: You can't add an interface to a bridge-group if it already has an IP address assigned.)

configure
delete interfaces ethernet eth0 address 192.168.1.1/24
commit

Here we add interface eth0 to br0.

set interfaces ethernet eth0 bridge-group bridge br0
commit
save

 

Both eth0 and eth2 are now bridged (same LAN).  We do however have a few more changes to make.  We need to change the DNS forwarder listen interfaces and remove the unused DHCP server.

delete service dns forwarding listen-on eth0
delete service dns forwarding listen-on eth2
set service dns forwarding listen-on br0
delete service dhcp-server shared-network-name LAN1
commit
save
exit

 

You now have an EdgeRouter-Lite 1WAN and eth0 & eth2 configured with a LAN subnet of 192.168.2.1/24.  You can do with with fewer steps if using a console cable or connected from the WAN (eth1) side. 

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