Known Issues:

  1. This router is one of the few that causes observable one-way audio intermittently that many customers often describe as dropped calls when it's just audio that cuts out and the other party disconnects the call.
  2. Software version 9.0.6h2d45 - Unsupported.
    • There is no ETA when a new software workaround will be available
    • Follow these steps:
      1. Get a recommended or serviceable router
      2. You or your IT will now need to setup the new router
      3. Bridge the Motorola NVG510 to the new router.  This article should help you:
        • Some firmwares may not allow putting more than one device in IP Passthrough. If you already have a device in IP Passthrough mode, it will have to be removed prior to adding your new router.
      4. Makre sure you move all of your phones off of the NVG510 and on to the new serviceable router once the bridge is completed.


    1. Set the expectation with all users in the office that this process will take at least 30 minutes and will require rebooting all computers and phones on the network after making the changes below.
      • It may also disconnect you from the internet for 15 minutes or longer.
      • Make sure to do this process during a time when you can afford to lose internet connection.
      • This process is safe, but if an unexpected issue arises, you may be offline longer than 15 minutes and may need to call your ISP to restore your internet connection.
    2. Write down the "Device Access Code" that's located on a yellow sticker on the side of the modem/router. You will need this later in the process.
    3. Use a computer that's on the same network as the phones.
      • Use Firefox or Internet Explorer.
      • Many customers have reported issues with this process when using Google Chrome.
    4. In the address bar of a Firefox or Internet Explorer, go to the following address:
      • If the NVG510's address was changed and is not, you will need to temporarily change the NVG510 back to use to use this process.
    5. Where it says 'Current software version' verify the firmware version is supported by this procedure:
      • 9.0.6h048 - Supported.
      • 9.0.6h2d21 - Supported.
      • 9.0.6h2d30 - Supported.

  1. IF YOUR NVG510 IS RUNNING SUPPORTED FIRMWARE: When the page above loads, right-click on it, select 'View page source' and search for:
    • <input type="hidden".
    • You should get something like:
      • <input type="hidden" name="nonce" value="815a0aaa0000176012db85d7d7cac9b31e749a44b6551d02" />.
  2. Copy the long string after "value", not including the quotes:
    • In the example above, that would be: 815a0aaa0000176012db85d7d7cac9b31e749a44b6551d02.
  3. Enter the long string in the box labeled 'Nonce value' this website and click on Save.
  4. At this point, you may see different things, depending on your web browser.  All of these are nothing to worry about.
    • You may see some text that says 'Error: Device or resource busy'.
    • You may get a message that the page couldn't be displayed.
    • If you see either of these, make sure that it says 'backdoor telnet enabled' or something similar.
    • You might also just see the normal Web Update interface with a 'firmware image is invalid' message.
  5. Reboot the NVG510.
  6. You can do this by going to the web address.
    • Important: it will reboot the router immediately so you will need to make sure no one is using the Internet and has saved all of their work before you open the link:
    • If the router doesn't come back up, you will need to manually powercycle it for 2 minutes.
  7. Once the router comes back, 'telnet' to the router using port 28.
    • Both PuTTYtell and the Windows Telnet client allow for this.
    • Important: port 28 is not the standard port for telnet.
    • You will need to remember this when 'telnetting' to the device.
  8. Log in with username 'admin' and the device access code as the password.
  9. At this point, you should see a prompt that says something like 'Axis/71158803050832>' (the numbers may be different).
  10. At the prompt, type: 
    • 'magic'.
    • Press Enter.
    • It should return (poof!).
      • Note: It may spit out 'Axis/7115880305032>' lines over and over again as shown below.
      • Just go ahead and type 'magic' press Enter.
    • Type: '!'.
    • Press Enter.
    • The prompt should change to '#'.
    • Type '/bin/cshell'.
    • Press Enter.
    • You should then be prompted for the login and password, use the same admin and device access code as before. The prompt should now read 'NOS/163607012168928>' (the numbers may be different).
  11. Enter the commands one-by-one below. If you get any error messages, double-check your work.
    • Make sure to enter the save and exit commands at the end.
    • Otherwise, you'll lose Internet connection:
      • 'config'.
      • 'set ip alg sip-enable off'.
      • 'set ip con name WAN icmp-echo-drop off'.
      • 'set ip dns primary-address'.
      • 'set ip dns secondary-address'.
      • 'set ip dns proxy-enable off'.
      • 'set security firewall-level low'.
      • 'save'.
      • 'exit'.
  12. Go back to the router, select Home Network > Subnets & DHCP and make sure Public Subnet Enable is Off.
  13. Reboot all phones and computers to clear their DNS cache.
  14. Make sure all phones are registering by testing inbound and outbound calls on each phone. Make sure all computers can access the Internet.
    • If they all can reach the Internet, the process is complete.
    • If some devices cannot reach the Internet, move on to the next step.
  15. Reboot the NVG510, any other routers, switches, servers, and computers for 5 minutes if you can't access the Internet. Reboot any phones that are still not working.
    • If you still cannot access the Internet on your computers and your phones still aren't registering, this means the DNS changes in the NVG510 haven't been saved.
    • The phones and computers should still be able to get an IP address from the router but they won't be able to resolve domain names.
    • Either a command above was missed or the NVG510 ran into a bug with affecting just an older firmware version.
    • So far this problem has only affected NVG510s running firmware 9.0.6h2d21.
    • You will need to walk through 'telnetting' from your computer back into the NVG510 and entering each command again.
    • As long as each command is re-entered correctly, you will need to reboot all network devices again and they should be back up in approximately 15 minutes.
    • If you still can't access the internet from here, contact your ISP.

Permenant Resolution:

If any of the above options are not present then purchase a recommended router:

  1. Purchase a recommended router if you do not have one already.
    • Intermedia cannot setup the new router for you, but your IT or the manufacturer of your new router can help you.  They will need to move settings from the old to the new router to ensure your computers and other devices on the network work properly.
  2. Call AT&T to assist you with placing the modem/router into "Pass-Through mode" or "DMZ+ mode".

Additional Resources: