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In my home network I am using a Linksys WAG120N WLAN Router. For one of my devices I need port forwarding, this works without problems. I have, however, noticed that after a while the port forwarding stops working, often when I was not home for some days.

I have noticed the following in the router section Gateway Status:

  • Internet Connection:
    • Login Type: RFC 2516 PPPoE
    • Interface: Down

Instead of Up the Interface was down, hence it also didn't display information about:

  • IP Address
  • Subnet Mask
  • Default Gateway
  • DNS

My internet connection, however, was fully functional and I could use the internet without any restrictions. On the same page is a Connect and Disconnect button. Even though the internet connection is working, the Connect button is enabled and the Disconnect button is disabled. But when I press Connect, nothing changes.

Only a router restart solves this problem.

So what's the reason for the interface shutting down? Do I have to contact my provider for that? In the help section of the router it only says:

The device’s Internet Interface is displayed.

What's that supposed to be?

EDIT Another observation:

It just happened again, while I used the internet. The router logs do not reveil anything, unfortunately. With my PC (Ethernet) I can still use the internet connection. Other devices (WLAN) have no Internet available until I restart the router.

share|improve this question

The status on the router appears to not reflect the interface's current status. (As shown by when you can reach the Internet despite it being in a DOWN state.)

So, either:

  • The interface went down, the router changed its status, and did not reflect it coming back up.
  • The interface never went down yet the router, for whatever reason, changed the status to down.

It'll be difficult to essentially impossible to determine, from the router's POV, why the interface went down. Consumer grade network device skimp on a lot of troubleshooting tools. Here are some suggestions:

  1. Enable logging on the router. See what the log indicates.
  2. Call your ISP and ask them if they show any outages on your DSL line.
  3. Check that your router has the latest firmware. It's possible your ISP has upgraded its specs or changed some technical specifics that your router does not currently support.
  4. Ensure the router has plenty of ventilation and all vents are clear. Heat is the enemy of all electronics, and consumer devices are notorious for breaking down easily.
share|improve this answer
I just checked the Cisco website, and it appears they do not have a firmware update for the router. Another thing to check would be to ensure your router has the settings/configuration your ISP expects. You will need to contact your ISP to confirm the settings. – John Sep 11 '12 at 23:38
I will give it a try, these are plenty of tips. – Mahoni Sep 11 '12 at 23:44

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