You have a Linksys Etherfast Cable / DSL router and are having problems with:

You can also try the Linksys Support page and Tech Helper for the router, or contact Linksys support via one of the following methods:

Customer Support Phone:800-326-7114

Finding updated Firmware

tip_hp-9299613 If it ain’t broke…!

Upgrading router firmware can sometimes cause more problems than it fixes!  Here are a few lthings to consider before you click that “Upgrade” button:

  • Check the Readme or other information that describes what the firmware will do before you do the upgrade.  If you don’t need new features and your product is happily doing it’s job… leave it alone and don’t perform the upgrade!

  • If you do need the upgrade, first download a copy of your existing firmware revision, or the closest earlier revision available.  You may need it in case something doesn’t work right with the new firmware.


Latest Linksys Router Firmware
[All firmware can be downloaded from this page unless otherwise noted]


Latest Firmware

Release Notes


Updated: 11/7/01


None available

Supports enhanced Internet security using ZoneAlarmPro TM and PC-cillin TM.

Updated: 9/26/01


click here

Supports ZoneAlarmPro and PC-cillin feature upgrade.  Pricing is $80 for a 4-pack of licenses.

Updated: 8/16/01


click here

BETA 2.39 [download]

None available

MIB File [download]

None available

Updated: 7/11/01

RELEASED 1.37.9b

click here

Updated: 7/16/01

RELEASED 1.1 Rel 02

click here

You must use a new Upgrade Utility with this router. Download here. (Windows only)

BETA 1.1 Rel 04 [download]

click here

You must use a new Upgrade Utility with this router. Download here. (Windows only)

Updated: 5/24/01

BETA 1.37.2 [download]

None available

Updated: 5/24/01

BETA 1.37.4 [download]

None available

Fixes UDP lockup problems & improves stability.

attentionsml-5631012Go here for release notes and downloads for previous versions.attentionsml-5631012

5/20/01 V1.38.5 RELEASE Information:

This firmware (V1.38.5) is approved for distribution by Linksys.

attention_blink-9935750 This is RELEASED firmware.  This means:attention_blink-9935750

  • Linksys will answer questions and provide support with any problems you might have.
  • Use the contact information on this page.

If you have problems, read the Firmware Upgrade Tips!

attentionsml-5631012This firmware may be used with the following products:

  • 1 port BEFSR11
  • 4 port BEFSR41
  • USB port BEFSRU31

Click here to see the Release Notes.

Updated 9/1/01Updating Firmware with a Mac

Linksys provides Firmware updates for the router in a Windows self-extracting zip file (.exe extension).  Although this file can be expanded via Stuffit Expander (you may have to change the .exe extension to .zip to get Stuffit to work its magic) to get the CODE.BIN file that contains the firmware, the Windows-based TFTP client that’s included with the update won’t be of much use on your Mac.

There are multiple ways to upgrade the Linksys firmware with a Mac-only network:

  1. Use Kem Tekinay’s MacTFTP Client.
    (This will work no matter what firmware revision your router has.)
  2. Use the built-in Java upgrade client.
    (This will work only if your router has V1.22 firmware or higher already installed.)
  3. Try using MaxGate’s MAC updater. (Thanks Jonathan Gahan!)
  4. Use MacTechnologies’ MacTFTP client (requires PPC and MacOS8.1 or higher).

TFTP method
Kem Tekinay of MacTechnologies Consulting has written MacTFTP Client.  This little shareware gem is a TFTP client that supports both Send and Receive to and from any TFTP server.  You just input the IP address of the TFTP server, type in the server’s password (if needed), select the file you want to transfer and hit the Start button. The program is free for 30 days, after which you’ll need to register.  Go here to download MacTFTP. (Thanks go again to John Strung for this tip!)


Java Upgrade Client method
Once you get the V1.22 upgrade into the router, you won’t have to hassle with a TFTP client again.  The V1.22 upgrade includes a Java-based upgrade page.

But, MacOs users who try to use the V1.22 firmware’s built in Java update page with Internet Explorer 5.0 or higher will probably find that it won’t work.  Reader John Strung reports that you can get around this problem by using Apple’s Applet Runner to execute the Java applet instead of the IE5.0 Java engine. Here’s what you do:
attentionsml-5631012NOTE: You must have V1.22 firmware or higher already loaded in the router in order to follow these instructions!

  1. If you don’t have the Applet Runner, download the MacOS Runtime for Java package.  Version 2.2 for MacOS 8.1 or higher is located here.

  2. Open the Applet Runner and unrestrict security settings in the Applet Runner’s preferences panel.

  3. Download and uncompress (using Stuffit Expander 5.0 or higher) the firmware .exe file from the Linksys FTP site.  (You might have to change the extension from .exe to .zip to get it to expand.)

  4. Move the CODE.BIN file in the expanded folder to the desktop.

  5. Type into the Location box in the Applet Runner.  (If you changed the default address of the router, change the to the address that you assigned to the router.)

  6. After the upgrade completes, remember to reboot your router and restore any special settings.

12/4/00 Updating Firmware with a Linux/Unix machine

Here are the Linux/Unix commands to upgrade the router
(thanks to Jean-Christophe Hugly for the info!)

attentionsml-5631012NOTE: You will need to temporarily remove any admin password from the router before upgrading the firmware. (Linux tftp doesn’t embed the password in the tftp WRQ (write request) packet as the Linksys requires.)  Restore the password after you’ve completed the upgrade.

This assumes the CODE.BIN file is in the current directory.

  • tftp <the fire wall IP Address>
  • mode binary
  • put CODE.BIN

Or instead of removing the password, you can try this command:

put CODE.BIN CODE.BINoctetpassword

where password is replaced by your router’s password.

(Thanks to Ben Galliart for this tip!)

Or you can patch the Linux TFTP program.  You can download a patch from here against tftp-0.16-5.src.rpm, courtesy of Jan Vilhuber.

new_ani-88614209/29/00 Updating Firmware with a OS/2 machine

(Thanks to Jean-Claude Desinor for the info!)

I have been using 1.35 with an OS/2 machine.

The procedure is the same as for Linux/Unix:

1) Temporarily remove the password through the Administration Web Pages

2) Exit your WEb browser

3) Go to the directory where the code.bin file is located

4) Type “tftp router’s_address>” to start tftp and connect with the router

5) Type “mode binary” to get into binary mode
(If you want to see the packets being sent, type “verbose”)

6) Type “put code.bin” to upload the code

7) Type “quit” to go back to the command prompt.


4/2/01 Firmware upgrade tips

The following tips may help you with the firmware upgrade process:

  • new_ani-8861420 Try the new TFTP2 upgrade utility.  Download from here.

  • It’s a good idea to download a copy of the existing version of your firmware from the Linksys FTP site, so that you can restore it in case something goes wrong with the newer version of firmware that you are trying to load.  If you can’t find your exact version, just download the latest released version.  If the Linksys FTP server is down, use the 1.30 version from here (this is the entire 1.8MB self-extracting “.exe” file).

  • Does the upgrade program successfully finish, but you can’t bring up the Admin page?
    Try backing off to the previous version of firmware and use the “Advance” button on the Upgrade Firmware program and set it to send Filename with path, and change the Initial delay to 1000ms. (Thanks to Timothy R. Davis for the tip.)

  • The TFTP upgrade server is burned into the ROM of the router, and can’t be erased.  If something goes wrong with the upgrade and you get the dreaded steady “Diag” light on the router, just repeat the upgrade.

  • If you are having a NIC connection problem, you may have an upgrade fail and not be able to resurrect the router.  DON’T PANIC!!!
    Either connect the router to another computer with a different NIC, or connect a hub between your computer and the router (don’t connect “Uplink” to “Uplink”, connect “Uplink to a NORMAL port), and retry the upgrade.

  • You might have a problem upgrading or logging into the router if you use too strong a password.  Some versions of the firmware are reported to have problems with mixed upper & lower case letters, or with characters other than numbers and letters.  Some users have been able to use their password successfully on the router, but have it fail when trying to use the TFTP upgrade client.

    We recommend trying to use as strong a password as possible, but if you have problems, try using a simpler password.  You should also stay away from the characters “/” and “\” in your passwords, keep the length under 39 characters, and do not use any spaces in the password (your browser will translate the space character to ‘+’).

  • Some firmware versions reset the password to “admin”, so try that if your normal password doesn’t work.

  • If you still have problems upgrading due to getting your password rejected, try entering a blank password, then try the upgrade.  Be sure to restore your password after you’ve successfully upgraded!

  • STILL can’t get the firmware to load? See this tip.

  • Here’s a copy of the installation instructions (Readme.doc) file that comes with the upgrade file:

    How to upgrade the BEFSR41 FirmwareThe firmware on the EtherFast Cable/DSL Router (BEFSR41) has a 512KB flash
    chip that can be upgraded with a new firmware. Please read the instructions below to upgrade the firmware.

    1. Double click on Tftp to install the Upgrade Firmware software. Follow the screen and accept the default settings by clicking on Next a few times, then click on finish to finish the installation.

    2. Click on Start, Programs, Upgrade Firmware, then click on Upgrade Firmware. You should see the screen below. 

    3. The following option is available.

    Server- Enter the IP Address of the BEFSR41 that you assigned. By default, the router is as shown above.

    Password- Enter the password you assigned the router. By default, the router’s password is “ADMIN”.

    File- Click the triple “…” button to browse for the code.bin that was part of the extracted file you downloaded. In the example, the code.bin was extracted on the Windows desktop. 

    4. Click Upgrade button to start upgrading. A progress bar should show up to
    show the progress.

    Upgrade is complete.

4/11/01 Reviving a “dead” Linky

If you follow this procedure, you should be able to successfully load firmware into your router, even if you think you’ve tried everything.  Follow the steps exactly and don’t skip any!
[Thnx to Mike Ronayne & Linksys!]

To reload the firmware when an upload fails or when the red error light is blinking, do the following:

1) Set a static IP Address on the Windows PC as following:

IP Address:

2) Make sure that you can execute the DOS command: “PING”.

3) Make sure that the file name of the firmware code, given to TFTP.EXE, is “code.bin“. RENAME the firmware file if you have to.

4) Try passwords in this order:

First: Try a blank password,
Second: Try “admin”  (don’t enter the quotes)
Third: The password you assigned previously

5) After successfully uploading the firmware, press the Reset button to clear memory and select default settings.

6) Reconfigure the LinkSys as required to support your Broadband environment.

Another reader suggested a simpler method for reviving Linky:

1) Press and hold the Reset button for about 30 seconds


Remove power. Wait about 5 seconds. Reapply power.

Linky should now be restored to factory default settings and you should be able to load firmware using the default password admin.