How to Extend your Wireless Access Point with a 2nd Wireless Router

LinkSys WRT54G(S)

I was getting spotty wireless performance from the side of my house opposite my router.  I have a LinkSys wireless router in my computer room on the main floor and in my unfinished basement is a computer work/repair/experiment area that my kid calls "The Geek Center".  The distance between the downstairs Geek Center and my main Internet gateway router is 90 ft. and is blocked by tile and hardwood flooring, walls, appliances, a widescreen TV, electrical wiring, plumbing, steel beams, and metal duct work.

Wireless signal strength from that upstairs router to the downstairs Geek Center is usually low and most times intermittent.  I do have a network cable run that connects the main floor computer room with the basement computer area but I wanted a strong wireless LAN capability throughout my whole house including the downstairs computer work area.

So among the options were:

• Replace my existing router to something more powerful.
• Buy hardware and make a central access point.
• Relocate the router.
• Do a 3^rd party firmware upgrade on the original router that would allow a theoretical increase in transmission/reception strength and/or install a better/different antenna.

I was recently given another wireless router - a neighbor gave me a LinkSys WRT54G as thanks for "fixing" his wireless connection.  I thought that there should be a way to use that to increase my coverage.  I'm always up for a challenge but I didn't know exactly what I was getting into.

Ideally, I wanted to be able to use both routers' wireless and wired capabilities but have wireless devices see only one WAP - using the same wireless signal, the same passkey, and be able to hand off seamlessly if the wireless device moves out of the range of one and into the range of the other.  In other words, I wanted the two LinkSys routers to act as one.

Impossible?  At first I thought so.  People who have more experience than me told me LinkSys wireless routers couldn't be configured to work that way.  I dug around and experimented with settings and found that it can be done.  Just so you know I didn't figure ALL this out on my own.  I went to several places to read what others had done to accomplish similar things and combined them with some time-consuming trial and error before I ended up with something that worked.

Overview:
The second router will be connected to the original router with a network cable using one of the regular jacks and not the Ethernet input jack.  After some configuration changes, it will function only as a wireless repeater and router.  The SSID, security mode, and passkey will be changed to be the same on both routers so wireless devices will see the two routers as the same and will automatically lock onto the one with the best signal.  The wireless channel will be changed on one router so there will be no radio signal conflicts.  The existence of two radio channels wont affect the handoff that will occur as wireless devices release one router and lock on to the other.

The secondary router will have DHCP disabled.  DHCP is the method by which servers assign local IP addresses to computers that share a local network.  In a LAN situation, its best if only one device gives out IP addresses.  The secondary router will also have its gateway role turned off to function as a router only.

Firmware Flashing
Probably the most important part of this procedure is flashing the firmware of the *secondary* LinkSys router with the 3rd-party flash from WW-DRT so that repeater capabilities are added and DHCP can be disabled.  Flashing basically changes the permanent programming of the router's hardware.  You will want to become very familiar with the pertinent info and flashing instructions on www.dd-wrt.com.  This site will guide you to the correct firmware flash for your specific router and version.  The firmware upgrade I used on my secondary WRT54G was the "DD-WRT Standard Version 24" (file name: dd-wrt.v24_std_generic.bin).

Pay attention to the firmware type that is meant for your particular router and version number.  For example:  If you have a LinkSys WRT54GS, that model only has 2MB RAM and will only accommodate the dd-rwt micro firmware flash file which is a smaller-sized version of the standard firmware flash.  The one with the GS suffix also requires two intermediate flashes before flashing with the final dd-wrt micro version so be sure and carefully read the instructions for flashing your particular router.

Important Disclaimer
If you have a spare Linksys modem, this will probably work for you but I'm not making any promises.  I tried to remember everything I did.  As is the case with firmware flashes, there is the outside chance that something could go wrong.  If the gods are frowning on you, you could destroy your extra router.  Eh... what the heck.  What are they $50 bucks?

During this procedure, be sure to not accidentally confuse the configuration interfaces of your two routers especially if your primary router is another LinkSys.  Keep in mind that right now, if you have two LinkSys units, both routers' configuration interfaces are accessed by the same IP address (192.168.1.1).  No changes to the primary router are necessary or desired at any point in this procedure.  As long as you don't change configuration settings in your original router, you will be able to happily go back to what you had before.  So please do something to insure that you do not mix up the configuration interfaces and unintentionally change settings in the original router.  If something does screw up, we want it to be the extra, secondary router.  Remember - all changes will be done to the secondary router - we won't touch the settings in the original, primary router.

If at any point during this procedure your computer loses its ability to connect to the modem's interface (provided your logon info is correct) try connecting to the Internet using your original connection.  If it fails and you are still connected to your original router, you can try to release and renew your IP address: Start> Run> type cmd, OK.  Then at the command prompt, type "ipconfig /release", hit Enter, then type "ipconfig /renew".  Enter.  In Win98 systems, its command, then ipconfig /release_all, Enter, then ipconfig /renew_all, Enter.

If you are disconnected from your original router and everything hangs, you will need to re-associate your computer with the original router.  If you aren't wireless, hook into your router using a Ethernet cable.  Assuming XP, go to Start>Run and type CMD, hit Enter.  A command window will come up.  Type in ipconfig /release and hit Enter.  This clears your IP Address info. Then type in ipconfig /renew.  This tells your router to reassign your PC new IP Address info.  If your primary router is still functioning properly, you should be back in business.

Here are the steps to transform a LinkSys router into a wireless repeater:

Go to www.dd-wrt.com and download the recommended firmware file(s) to your desktop.  In most cases it will be a single .bin file.  Close (disconnect from) all wireless connections on your PC and unplug all wires between your PC and the primary router.  Unplug the Ethernet cable from your secondary router to separate it from your network.

On your secondary router, do a "hard reset" by holding in on the reset button for 30 seconds.  This resets all user changes made to the router's memory chip (encryption, passkey, access password) back to factory defaults.

Connect the PC to a regular port on the secondary router and again check to be sure you are disconnected from the network (both wireless and wired).

Go into the secondary router's configuration properties - for LinkSys use 192.168.1.1 (user: admin, password: admin).  Again - be sure you are unplugged from the Internet and it's just your PC and the secondary router connected by a cable especially if your primary router is another LinkSys.  Close all wireless connections.

Firmware is upgraded on the Administration tab.  Most LinkSys routers are upgraded by navigating to one .bin file.  The exceptions are routers like WRT54GS where there are extra steps which will be described on www.dd-wrt.com.  Browse to the bin file you downloaded and let the flash begin.  Let it finish completely or you will end up with nothing more than a cool black and purple spaceship for your kid to play with in the bathtub.

Sign back into the configuration properties using 192.168.1.1.  The flash will change your logon info.  If "admin/admin" doesn't get you in, try "root/admin".

Once you are back into the secondary routers configuration interface, do these settings changes:

Setup> Basic Setup >Router IP - change the number from "198.162.1.1" to "198.162.1.2".  Change the default gateway to 255.255.255.0. This change is necessary to make the LAN distinguish it from your other router if it is also a LinkSys.  If it is not, you can omit this step if you want.  Click Apply Settings.  You have just changed the network IP address of your secondary router and from here on, you will now access the secondary router's configuration interface using the IP 192.168.1.2 (user: root, password: admin).  If your main router is a LinkSys, this will also prevent you from making accidental changes to it which is still accessed using 192.168.1.1.

More settings changes on the secondary router:

• Setup> Basic Setup> WAN Connection Type:(dropdown) "Disable"> Apply Settings
• Setup> Basic Setup> DHCP Server:(radio button) (radio button) "Disable"> Apply Settings
• Security> Firewall> (radio button) "Disable"> Apply Settings 
• Setup> Advanced Routing> Operating Mode: (dropdown) "Router"> Apply Settings
• Administration> Management > Routing: (radio button) Disable> Apply Settings
• Wireless> Advanced Settings> Wireless GUI access Enable or Disable - your choice.  You either need to disable Wireless GUI access or change the router logon password in Administration> Management to something other than "admin" then click Apply Settings.  Remember that your logon will no longer be "root/admin".
• Wireless> Basic Settings> Change the SSID name of the secondary router to something you would recognize in a list of available wireless networks in your wireless networking utility.  You also need to know the name of your original router to be able to distinguish between the two.  Also change the frequency to something other than what your other router is using.  I suggest the original router use channel #6 and the additional one be set on #1.
• Administration> Management > Reboot Router
   

Now plug a network cable from your original router (gateway) into one of the device ports of the router you've been working on.  Do NOT plug the original router into the Ethernet port of the secondary router.

Go into a wireless device's (laptop) wireless network interface to "View Available Networks".  You should see your original router and also the one you just configured.  Try connecting to and unconnecting from each one individually to make sure they both work and traffic passes like it's supposed to.

If this works, you're home free except for these last important settings:

Go into the secondary router's configuration interface again (remember that you changed the logon password).

• Wireless> Basic Settings> Change the SSID name to *exactly* match your primary router.  We want the two routers to have the same name.
• Wireless> Wireless Security> Select the exact same Security Mode as the primary router (I recommend WPA Personal TKIP) and also change the passkey to the same as your primary router pick a non-guessable password with letters and numbers.
• Reboot the secondary router.

These last steps are necessary to combine the two routers as far as wireless devices are concerned and was the desired result of all this.

One thing to note is that having two wireless routers with the same name on two different radio frequencies may confuse the strength meter on Windows Wireless Connection interface.  Even though it may show low strength on the meter, it will perform as a high-strength connection.

You should now be in business.

So, do you think it would be worth it to try?  Probably not unless you had an extra router lying around and wanted to play.  For me, this was interesting to do and after doing all the trial and error, I think I know these LinkSys routers pretty well.