31 Juli, 2011

Linksys E4200 - HOWTO: Wireless Highspeed Bridge

Use 2 Linksys e4200 routers to "bridge" some distance in your house where cables cant go or would be too much work...

My situation: I wanted to connect my livingroom (Satellite HDD Receiver, Wii, PC) to my homelan. I had this before - but only using powerlan (network over the powerline). This is slow - no matter what they write on their ads... (around 0,5MB/s)

So I decided to buy 2 of the currently best routers and get them connected at the currently highest available wireless speed - 450mbit on 5Ghz (802.11N).
The good on this routers: they can do both - 2.4Ghz and 5Ghz at the same time. So you can bridge two of them together and have both acting as access-points - without loosing much performance. Another great aspect of the e4200: the wireless signal is really strong - giving you wifi nearly everywhere in a big house!

Step1 - download DD-WRT firmware
On the standard firmware as they come, they don't have the option to be wireless bridges, or WDS repeaters or however you may call it...
So download the very good open source alternative: DD-WRT
I use: DD-WRT v24-sp2 (04/13/11) std-usb-nas
Download here or search "e4200" at dd-wrt.

Step2 - do a 30-30-30 reset:
- while running, press and hold the reset swith on the router for 30sec
- unplug the power cable while still pressing the reset swith - wait another 30secs
- then replug the power and hold the reset for another 30 secs
I'm not really sure if this was neccessary - but I did like I was told...

Step3 - install firmware
To install it, you just follow the normal firmware upgrade procedures (not sure now where this is at the standard routerpages - as I have only the modified software on both routers here). On DD-WRT they write a good FAQ how to install the firmware.

Step 4 - setup both routers:
I'll just copy my config here and hope you know how to adapt these settings to match your homelans IP address range...

Router1 - Main accesspoint - connected to homelan and internet:

Interface WL0 (normal Wifi 2.4Ghz)
Wireless Mode: AP
Wireless Network Mode: mixed
SSID: normalwifi
Channel: auto

Interface WL1 (Bridge WIFI - 5Ghz)
Wireless Mode: AP (important: both routers have to be AP - not client bridge as I thought!)
Wireless Network Mode: N-only 5Ghz
SSID: bridge
Channel: 120 (choose what you like - but the same on both routers!)
Channel Width: 40Mhz
Control Channel: upper
SSID Broadcast: disable (could be enabled at first tests)
Network config: bridged

Wireless Security:
wl0: WPA2 Personal mixed / TKIP+AES
wl1: WPA Personal / AES

WDS Settings:
LAN and the MAC address of your other routers WL1 mac address (can be found on his configpage at the same spot as you are here (Wireless / WL1-WDS)
This tells the router here which other router can connect as a bridge to him. The same has to be done on the other router with this routers MAC (found right here). Confuesd? :-)

Router2 - router in livingroom:
Basicly just setup both routers the same way. Only difference is in the WL1-WDS section where you have to specify the MAC address of the other router.

If you did everything right, you can now unplug the LAN cable from the "livingroom" router (.251) and try to ping it - if it works - congrats - your wireless bridge works! (coming here took me nearly a day - if you were faster - your either more intelligent, luckier or my guide helped :-)

You can see on the Status / Wireless section under the point "WDS Nodes" if there is the other router. Can take some time - but if you have a working bridge - it should come up here and also show's you your signal-quality - mine is 24% through 3 walls - not perfect - but still gives me around 5-6 mb/s (megabytes per sec - or 40-48MBits) that's far more I ever got with other wireless systems and comes close to 100 MBit Lan cable speed. This way 1GB file transfer only takes ~3mins!

Tip on restarting the routers (and their bridge):
I found, that if I only restart one router - the bridge wouldn't work after the restart until I use the right order:
first restart the client - livingroom router (although both should be equal)
the wait some time and then the "main router" - connected to the internet)
So I set timers on the powerplugs and let the livingroom router start earlier in the morning...
Since I did this - the bridge works without a problem. You surely could let them run forever - but I like to save power by shutting down devices in the night...

If you read this and it helped please let me know by commenting here.
or read and comment on Experts Exchange here: Linksys E4200 - HOWTO: Wireless Highspeed Bridge