LAN Port Fried?

[Eric T]

Had a close lighting strike recently in the evening and when turning my desktop on the next morning discovered I had lost my internet connection. After swapping out some cables and messing around it appears one of the LAN ports on my RT-AC66U has become non-functioning.

The LED for LAN #3 is does not light and no connection is made when plugging a device into that port.

I did see the LED for the port flash on during a re-boot but other than that it remains dark.

Any ideas how I can determine if that port was in fact damaged? I re-booted the router, don't know what else I could do.

Thanks

 

[coxhaus]

I have had that happen before. The lightening strike burned out only the ports which had wires connected to them on a switch.

 

[Eric T]

I had no damage to my computer luckily....I had the ethernet cable going in and out of a battery backup / surge protector unit that probably saved me there.

Looks like I will just need to live with my router missing a tooth. It appears to be functioning normally otherwise.

 

[RMerlin]

I had no damage to my computer luckily....I had the ethernet cable going in and out of a battery backup / surge protector unit that probably saved me there.

Looks like I will just need to live with my router missing a tooth. It appears to be functioning normally otherwise.

One thing to try is to fully drain your router of any power, to ensure a complete reset of the electronics inside. I've had USB ports brought back to life this way. Follow this procedure:

• Turn off the router
• Unplug all cables, including power
• Turn the router on (WITHOUT the power cable). That will drain any left over power still inside the router's capacitors
• Turn it back off
• Replug everything
• Turn it on normally, and see if it works

 

[Eric T]

I gave it a shot but, no luck. Port 3 is playing dead. Thanks for the advice though!

I happened to have a spare Netgear N300 wireless adapter to use at my desktop to make up for the dead LAN port I need. I'll just use that for now. Maybe another lighting strike will completely burn the router up and I'll be able to justify getting a new one.

 

[coxhaus]

If it was me I would use a switch and only use one Ethernet port on the route connecting to the switch. I think it will run better that way as all the local traffic load is on the switch and not the router.

 

[RMerlin]

If it was me I would use a switch and only use one Ethernet port on the route connecting to the switch. I think it will run better that way as all the local traffic load is on the switch and not the router.

The four ports on the router are actually a switch, so traffic between two LAN ports never gets processed by the router itself.

 

[coxhaus]

The four ports on the router are actually a switch, so traffic between two LAN ports never gets processed by the router itself.

So is the level 2 switching handled by a separate CPU versus level 3 routing?

 

[RMerlin]

So is the level 2 switching handled by a separate CPU versus level 3 routing?

There's no CPU at all involved. It's just a switch.

 

[Spindizzy]

Similar Problem Fixed RT-AC66U dead LAN port

I recently replaced a cable that had been physically damaged. When I did so, the port it was connected to (1) ceased to operate. It would blink on bootup, but it would never connect to the device on the other end. As far as the device on the other end was concerned, there was no connection to the router.

After trying multiple things, I got desperate and tried the following.

1. Make sure there's a known working device connected to the 'dead' port.
2. Save your configuration: Administration -> Restore/Save/Upload Configuration -> Save. Remember where the file is, you'll need it.
3. Restore Factory Default: Administration -> Restore/Save/Upload Configuration -> Restore. In my case, as soon as the restore was finished, the previously 'dead' port lit up.
4. (Don't know if this step is necessary, but I did it anyway.) Work your way through the Quick Internet Setup.
5. (If the 'dead' port isn't lit up now, this is probably not working for you, but you need to finish anyway to get your configuration back.)
6. Restore your configuration (1) Administration -> Restore/Save/Upload Configuration -> Choose File (This is where you need the file you saved earlier.)
7. Restore your configuration (2) Administration -> Restore/Save/Upload Configuration -> Upload.
8. Finished.

At the worst, you'll be back where you were before you started. At the best, your dead port(s) will be working again.

Hopefully Helpful!