Use B3 WAN port to extend LAN

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Anonymous777
Posts: 6
Joined: 30 Oct 2011, 18:29

Use B3 WAN port to extend LAN

Post by Anonymous777 » 08 Mar 2012, 17:25

Hi,

I use B3 as server inside LAN (no routing) behind a DD-WRT router / DHCP server with port forwarding. Sadly, I ran out of free LAN sockets on that.

But there's a free WAN port on B3 left! There should be a way to configure it to act as an extension for LAN. To make B3 to act as a switch, so to say. Can anybody help me?

A small illustration, what I try to achieve:
Screen Shot 2012-03-08 at 23.11.42 .png
Screen Shot 2012-03-08 at 23.11.42 .png (23.11 KiB) Viewed 4135 times
Sure I could attach B3 to DD-WRT using WAN port and the extra device to LAN port, but that would create unneccesary NAT and extra subnet. Goal is that all devices are on the same subnet.

Thanks!

RandomUsername
Posts: 904
Joined: 09 Oct 2009, 18:49

Re: Use B3 WAN port to extend LAN

Post by RandomUsername » 08 Mar 2012, 18:17

Posting from my phone so excuse the brevity, but you can bridge the two ports together quite easily.

First, install bridge_utils I think the package is called, then just modify /etc/network/interfaces.

I actually have a B2 at work with this set up for network monitoring. I will try to post the config tomorrow when I'm there.

EDIT: Forgot to mention, I first stripped the B2 right back to basic Debian but you probably don't have to go that far.

Gordon
Posts: 1388
Joined: 10 Aug 2011, 03:18

Re: Use B3 WAN port to extend LAN

Post by Gordon » 10 Mar 2012, 16:03

My guess would be that bridge-utils is already installed as it is required for the default network setup in the B3-wifi ;)

Anonymous777
Posts: 6
Joined: 30 Oct 2011, 18:29

Re: Use B3 WAN port to extend LAN

Post by Anonymous777 » 10 Mar 2012, 19:51

RandomUsername, thanks, worked great!

just had to change bridge_ports eth1 wlan0 to bridge_ports all wlan0
+ add bridge_hw directive, otherwise B3 gets IP over DHCP using MAC of WAN port instead of LAN

Gordon, yes, they were installed per default

Anonymous777
Posts: 6
Joined: 30 Oct 2011, 18:29

Re: Use B3 WAN port to extend LAN

Post by Anonymous777 » 11 Mar 2012, 15:03

Hey, I just understood how cool is this configuration if your router/switch is not gigabit, but only 100m. Now I can hook up my devices directly to B3 for occasinal data-intensive tasks, like initial backup for (almost) 10x more speed :)

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