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 main wireless router which is the gateway to my Internet.  My computer room is on the main floor and in my 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 Cat5 Ethernet 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 dedicated 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.
• Use a spare LinkSys WRT54G wireless router I already had to create an additional Wireless Access Point (WAP)

The last option made the most sense.  Dedicated access point hardware could run over $100 but these Linksys wireless routers are inexpensive - $50 USD new and $20 used on eBay and you also get the benefit of the switch ports on the rear of the added Linksys.

Ideally, I wanted to be able to use both routers' wireless capabilities but have client wireless devices see only one WAP - use 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 wireless access points to act as one.

For clarification purposes, I'm going to refer to the additional LinkSys WRT54G as "LinkSys2".
The original router will still be referred to as the "original router".

Overview:
The secondary additional access point (LinkSys2) will be connected to the original router with a network cable using the LAN uplink jack on LinkSys2.  After some configuration changes, it will function only as a wireless access point.  DHCP and routing functions will be disabled.  The LinkSys2 will have its own static IP address which will be in the original router's own subnet.  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 radio channel will be different on the two routers so there will be no radio signal conflicts.

Firmware Flashing
Probably the most important and delicate part of this procedure is flashing the firmware of the LinkSys2 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 LinkSys 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
If you have a spare Linksys WRT54G, 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... take a chance.

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 probably 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 (aside from a possible radio frequency change).  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 - most all changes will be done to the secondary router.

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 or Vista, 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.  In Win98 systems, it's command, then ipconfig /release_all, Enter, then ipconfig /renew_all, Enter.  This tells your router to reassign your PC new IP Address info so you can communicate again.  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 access point.

Part 1.  Firmware Flash

• First, make note of your primary router's IP information.  I don't know the brand or model of your original router - you're going to have to get this info on your own.  Go into the router's interface (LinkSys is usually 192.168.1.1) and note the following:

  • The static IP address of the router itself

  • The range (pool) of IP addresses that it will assign

  • Find out the IP address it has recently assigned your computer (Start>Run>cmd, at the prompt type ipconfig.  Write down the IP address.

  • Security settings: SSID (this is the name you gave your network.  It can be changed to anything.), Security Mode (recommend WPA-PSK aka WPA Personal), Algorithm (recommend TKIP), Passphrase

  • Save this stuff - you'll need it later

  • While you're in the original router's interface, change its radio channel to 11 if it's not already there.  It just works better.
     

• 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.  After downloading, 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 LinkSys2 router to separate it from your network.
   

• On your (secondary) LinkSys2 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 (NOT the Uplink Port on the end) of the LinkSys2 and again check to be sure you are disconnected from the network (both wireless and wired).  It should just be your computer hooked into the LinkSys2 using an Ethernet cable.
   

• Manually set your computer's IP address so it can talk to the LinkSys2 router.  Here's how.  Open Network Connections (XP: Control Panel>Network Connections or Vista: Control Panel>Network and Sharing Center>Manage Network Connections).  Find your wired NIC entry.  If you are on a laptop, you will have an entry for wired and wireless.  Right-click and disable the wireless adapter, and right-click and enable the wired adapter.  On the wired adapter, right-click and choose Properties.  Choose TCP/IP (v4) and click Properties.
  
  Click the radio button "Use the following IP address" and enter the following:

  • IP Address     192.168.1.2

  • Subnet Mask  255.255.255.0

  • Gateway        192.168.1.1

  Click OK and close.
   

• Now you should be able to talk to the LinkSys2 router.  Go into its interface by opening a web browser and typing in 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.  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.  Now your credentials will be user: root, password: admin.

Part 2.  Configure the newly flashed LinkSys router

Go back in using 192.168.1.1.  The dd-wrt interface looks differently than the old LinkSys interface.  Let's make some changes.

* Note: On these screens, click SAVE and not APPLY SETTINGS.  APPLY SETTINGS will be our last step.

• Setup> Basic Setup tab
  • WAN Connection Type:(dropdown) "Disable"> Save
  • Router IP (got your primary router's IP address info handy?):
    • Local IP Address: Use an IP address that is in the address pool that you wrote down from your primary router.  Choose one that is on the opposite end than what was assigned to your computer.  Example:  Assignable address pool is 192.168.1.100 through 192.168.1.200.  Computer IP from ipconfig showed 192.168.1.9, then you will choose 192.168.1.199.
      
      Remember this address!  This is the new IP address of LinkSys2 and will be the one you use to access the interface in the future.
       
    • Subnet Mask:  Same as primary router (usually 255.255.255.0)
    • Gateway:  Use primary router's IP address
  • Assign WAN Port to Switch: Check this box
  • Network Address Server Settings:
    • Disable DHCP
    • Uncheck BOTH DNSMasq boxes
  • NTP Client: Disable
  • At the bottom, click Save (NOT Apply Settings)
     
• Wireless>Basic Settings tab
  • SSID:  Type the SSID name from your original router.  Must be exact.
  • Change Wireless Channel to 1.
  • Save (NOT Apply Settings)
     
• Wireless>Wireless Security tab:
  • Mode, Algorithm, Passkey - use the same as your original router.
  • Save (NOT Apply Settings)
     
• Services>Services tab:
  • Disable DNSMasq and ttraff Daemon
  • Save (NOT Apply Settings)
     
• Administration> Management tab
  •  Info Site Password Protection:  Enable
  • Save (NOT Apply Settings)
     
• Double-check above settings.
   
• NOW you can click Apply Settings and exit the interface.
  
  * Note:  To access the LinkSys2 interface in the future, you will now use the new IP address you gave it when you changed it's local address.

Part 3.  Hook back up

Plug a network cable from your original router into the Ethernet port (Uplink port) of the LinkSys2 router.  The LinkSys2 should now function as an additional wireless access point and the four ports in the back of it should function as switched ports where you can plug additional computers.

Oh.. and let's put your computer's IP configuration back like it was.

Go into the computer you were using and undo the manual IP address changes we did in Part 1.  Open Network Connections again.  If you disabled the wireless and enabled the wired adapter entries undo those changes.  Open the properties window of the adapter where changed IP address and select "Obtain an IP address automatically".  You probably should check the TCP/IP (v4) settings of both adapters to make sure they are set to obtain automatically.

Click OK and Close.  If you were working with a laptop and you just now re-enabled its wireless adapter, it should have Internet access.  If it was a wired computer, go ahead and plug in an Ethernet cable.  It should now be automatically be obtaining an IP address.

You can test your new access point by checking the strength meter of your laptop when it is near it.  Also there are free utilities that show available wireless networks.  I like Vistumbler (Google it).  It shows all nearby wireless access points that are visible.  Your network should have two entries in the list because of the different radio frequencies we assigned the two access points.
 

Recap.  Here's what we did:

• On the LinkSys2 unit, we disabled the Internet Connection and we assigned the WAN (Uplink) port to the switch.  This allows us to plug an existing Ethernet cable into the Uplink jack of the LinkSys2.
   

• Disabled DHCP so that IP addresses are only given out automatically by the original router.
   

• Changed the role of LinkSys2 to a wireless access point (WAP) and switch.  It no longer functions as a router.  All traffic should move smoothly through LinkSys2.
   

• Changed the IP address of LinkSys2 to one that it is in the same subnet as the original router and we picked one that will not likely be used because it's on the other end of the scope.  LinkSys2 is now accessed by this new IP address and not 192.168.1.1.
   

• Gave the LinkSys2's WAP the same network name (SSID), security settings, and passkey as the original router but changed the radio signal.  This allows wireless device roaming and a seamless handoff when moving out of the range of one and into the range of the other.