LinkSys WRT110 Firmware Upgrade

Howto: Upgrade a Linksys Router's Firmware. This same article will work with most other brands of routers. The Firmware needs to be upgraded now (2010.07) in order to patch an exploit and this may also help resolve network stability problems dealing with IPv6 addresses.

This article is for an older router, but still can be used as a reference.  A newer article can be found here:  Yearly Router Updates.

Your home network may have a Cable or DSL connection. In either case, your PC connects to a router using either a wired or wireless connection. The device the PC connects to is the one this article addresses. In particular, this article shows how to upgrade a LinkSys WRT110 router. If you have a different brand or model, the steps are similar.

Here is a typical router layout in a home network.

* If you are a DSL customer and your PC connects directly to an ActionTec DSL Modem, and no other router is involved, then this article is not appropriate. If you have a secondary router, where all your PC's and printers plug in, and that router plugs into the Actiontec (illustrated above), then continue with this article. Your router may look like either of the two shown above.

* Ideally, you should perform these steps with a physical wired-connection (rather than wireless); this is safest. But, with that said, wireless will work.

Upgrading the router is easy and hard at the same time. It will be easy if you have documentation showing your router setup, IP Addresses and login accounts. If you don't, then this article will not help and the only good way to resolve this is to completely rebuild the network.


Determining your Router's IP Address:

You may have documentation for your router's (internet) IP address, but most people do not. However, it is easy to guess the correct address.

1. Open a DOS Prompt:

Start, Run, type "CMD" and press Enter
If the RUN command is not visible, see this article: Exposing the Run command

2. At the C:> prompt, type "ipconfig" (without quotes); press Enter

3. In the report, look for your workstation's IP Address (it may be displayed as IPv4 Address):

(click illustration for larger view; click right-x to return)

Typical results (may vary, depending on your setup) - note this will be your PC's address, not the router's -- but this will give you a hint:
192.168.1.100
192.168.1.2
10.200.150.50

Take whatever address is displayed and "lob-off" the last octet (last section) and mentally replace it with a "dot-1". Think about it this way: "192.168.1.100" becomes "192.168.1.1"; "10.200.150.50" becomes "10.200.150.1". The dot-1 address is probably your router's address.

Optional test: From the same DOS Prompt, type this command:
Ping 192.168.1.1

(-- replacing the address with the address you suspect. Press enter to run the command. Look and see if the device responds within xx milliseconds.)
You can also guess the router's IP address by assuming the router was set up with these vendor defaults; most people leave them at these settings. However, when the network was built, it may have changed. Between this list and doing the test above, you should figure out the address:

Default Router Addresses, by vendor
192.168.1.1 Linksys
192.168.0.1 Dlink
192.168.0.1 NetGear
192.168.123.254 USRobotics

But keep in mind, the addresses can vary, depending on who set up your network. For example, with my home network, I configured my Linksys router as "192.168.200.1".


Logging On to the Router

Once you know the IP Address, you can use the address to logon to the router's main configuration/administrative screens and begin the BIOS upgrade.

All modern routers are configured in a web browser. Follow these steps. For best results, use Internet Explorer (especially when flashing the BIOS) - some routers, particularly Linksys, fail if you use a different browser.

• From any PC in your internal network, open Internet Explorer
• In the URL line, type the Router's IP Address (e.g. 192.168.1.1)
• Do not type your computer's IP Address

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Note: Do not use Firefox or other browsers for these steps.
Linksys Bios Flash fails with this error:
"Please designate the path of the new Firmware".
You must use IE.

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If all goes well, you will arrive at a (Linksys) login screen.

Your Next Hurdle: The Password

At the login screen, type the router's administrative password. Hopefully, you have this documented. If you can't login because you don't know the password, you can try the router's default passwords, with several brands documented below. I tape my password on the bottom of the router.

For Linksys Routers, leave the UserName field blank and type the password.
(Note: newer linksys routers use admin/admin)


Vendor Default Passwords:
Linksys routers use these defaults:
username=(blank), password=admin
username=admin, password=admin

Dlink routers, depending on the model, use a variety of defaults:
username=admin, password=admin
username=admin, password=(blank)
username=(blank), password=admin
username=user, password=(blank)

Netgear:
username=admin, password=password
username=admin, password=1234
Security Blunder: If you manage to get logged in with one of these default username and passwords, your network is at risk - especially if you have a wireless. This means any of your neighbors or somebody driving by, can log into your router and do all kinds of nefarious things.

What if you don't have the Password?

If you still cannot log in, you will not be able to upgrade the BIOS.
The only other option is to rebuild the entire network by re-setting the router's BIOS to factory defaults and re-connect each PC and printer on the network. The instructions for doing this are beyond the scope of this article.


Confirm the current Router Version:
Assuming you are logged into the Router's administrative screens:
At the Router's banner screen, look for the router's Model Number and Firmware Version. These may be in the Status menus, but on most newer linksys routers, it can be found in the upper-left corner of the main screen. My router's firmware was 1.0.04:




Download Latest Firmware:

Note: Newer routers do not require you to manually download firmware.  See this article for details:
Yearly Router Updates.

1. In another browser Window, browse to LinkSys's support site: http://homesupport.cisco.com/.

2. "Search" for your model number (in my case, "WRT110")

3. Choose "Downloads"

Select the Hardware version. In my case, only Version 1.00 is available. On older Linksys Modems (with dual antenna), turn the modem over on its back and look for the hardware version on the tag; you will probably see versions 1 through 4.

4. Download and save the latest Firmware to a known location on your local hard disk. You are looking for a ".bin" file. Some older Linksys downloads are ZIPped; expand the ZIP, looking again for the .bin file; copy the .bin to a known location.


Apply the Firmware:

5. Return to the Linksys banner screen (the router).

6. Choose Administration, "Backup Configuration" Save the backup of the current Router to a a local file. I recommend naming the file as "YYYY-MMDD-config.bin" (with today's date).

7. Choose Administration, "Firmware Upgrade".

Browse to the downloaded ".bin" file (not the YYYY-MMDD backup file). In my case it was "FW-WRT110_WRT100_1.0.07.002_EN_20091123.bin".

Click "Start to Upgrade"

The upgrade takes about 2 minutes. You cannot interrupt this process or else you will corrupt the BIOS on the router. (Be sure there are no thunderstorms in the area).

8. Once the upgrade reports successful, you will loose your connection to the router; this is normal. Re-type the IPAddress to get back in.

If the upgrade fails with "Please designate the path of the new Firmware", you are probably using a non-IE browser. You must use Internet Explorer to do this step.

This completes the Router's upgrade.

Check Firmware versions Periodically:
Occasionally you should check the firmware on your Internet Routers for updates. I check about once every six months or so. Updates are needed for bug fixes and now they are sadly needed for security issues. Security breaches on routers are a relatively new exploit, see this alarming article: Forbes: Millions of Home Routers.


Windows 7 and Vista Network Failures:

If you are upgrading the router because of numerous network failures, you may also be interested in this article: Windows 7 and Vista Network Problem -- IPv6 incompatibilities. Applying the recommended changes in this article made my network completely stable.


Related articles and Links:
Windows Vista and Windows 7 Network Problem
Setting up a Home DSL/Network
Router Testing Steps

Forbes article: Millions of Home Routers to be Hacked
Determine External IP Address: http://checkip.dyndns.org/
General Router IP Address Information