Router losing internet signal when PC shut down

[tackify]

Hi all

Got a call to connect a cable modem to a Belkin router that a customer bought and gave up trying to set up himself. Got there and did the usual: disconnect everything; get the mac address of the eth card on the computer originally set up with Comcast (I know that Comcast binds to the mac address); connected the cable modem and let it boot completely; connected the router and powered it up completely, set it for dynamic, cloned the mac address from the original computer; ... and I had a connection, so I set up the wireless and no problems.

Until I shut down the original PC. Then I lost the internet connection at the router and I had to boot the PC and reboot the router to get it back. Happens every time. Pulled the Belkin and tried an Asus I carry with me. same behavior. The customer said he never shuts down that PC anyway so he was happy wiht it as is. Put the Belkin back in and told the customer I'd find out what's wrong and fix it when I'm back with him next on another matter.

I'm thinking I have to start clean: reset cable modem, reset router and reconnect everything and reconfigure router. But I don't know why what I did today didn't work.

Any thought are appreciated.

(naturally I got a call a couple of hours later saying he'd had to reset the router 4 tomes in 2 hours to keep his wireless connection with his laptop- I'm sure because I forgot to check his power management settings on the original PC and he lost the connection every time the PC went to sleep, so now he wants me back there)

 

[Crgky127]

So Comcast wanted the MAC of the PC and not the modem?

 

[tackify]

So Comcast wanted the MAC of the PC and not the modem?

Yup, as I understand it, it's part of their master plan to keep "unauthorized" computers from connecting to their system by binding to the MAC of the first computer attached to the modem.

As I keep digging around on this, it looks like perhaps if I unplug the modem for 5 minutes, it should flush out any previous MAC info it had stored. Then I can connect the router alone to it and let it fully connect to it (thus letting the cable modem bond to the routers MAC address), and then connect the router to the PC and set it up.

I've probably set up 20 of these things and never had to do this before, but it seems to make sense and would be worth a shot.

 

[trapped]

I see that a lot with Comcast. You should only need to disconnect the cable modem for about 45 seconds for it to forget the MAC. If it is a VoIP modem you also need to pull the backup battery. I would also disable the MAC clone and see if that works.

 

[vdub12]

I have had comcast for about 3 years and used a few different routers and 2 different modems and never had to do any mac address cloning.

Its always just worked. It has however always been attached to a router from day one.

I remember having to do that years ago with Comcast but i don't think they do it anymore, to may complaints from customers.

 

[NeutronTech]

I've never worked for Comcast, but I have worked for two other cable providers in-house. Cable modems do bind to the mac address, but not they way you describe. It's auto detected. If you swap a device then you usually need to power cycle the modem. There is no need to clone the mac address. Just connect the modem to the router and connect the pc(s) to the router. That's it. Now, if you for some reason needed bypass the router and connect directly to the computer then you would have to power cycle the modem again.

One of the companies I worked for gave out 3 IP address to each customer. With them you didn't need to power cycle when you bypassed the router. When you unplugged the router and hooked directly to the computer it just grabbed one of the other 2 IPs and gave it to you. Then when you hooked the router back up, the router had it's original IP again.

I think you created your own problem there with the cloned address.

 

[NeutronTech]

So Comcast wanted the MAC of the PC and not the modem?

No. Comcast still needs to modem's mac address to provision the modem. But he's saying he cloned the enet adapter on the pc into the router settings thinking that Comcast bound the IP to the computers mac address. They bind the IP to whatever device is connected to the modem automatically. If it is the router's mac then you can plug and unplug computers into the router all day long. But if you disconnect the router and want to connect directly to the PC, you will have to power cycle the modem so it can bind to thew new MAC.

 

[tackify]

OK, update time...

First, thanks to all who responded.

Went back to the customer and tore into the problem setup.

I unplugged the modem for 5 minutes

Reset the router via it's reset switch

Disconnected the Desktop from the network completely and connected the router to the ethernet port of a netbook I carry

Plugged in the modem and let it power up completely

Plugged in the router and let it power up completely

Turned on the netbook

and...

I had an internet connection. So I set up the wireless, got it running, and rebooted the netbook.
Had an internet connection, and everything worked as expected.

So I shutdown the netbook, still had an internet connection at the router, and plugged the ethernet cable into the desktop and booted it.

Had an internet connection.

Shut down the desktop, lost the internet connection at the router.

So, much at the prompting of my customer, I called Belkin for support. Their service tech put me through a procedure that was pretty much the same as what I had done, with the exception being that there was a firmware update that we applied. After doing this he declared the problem fixed. I suggested he stay on the phone until after we saw the internet connection survive a shutdown., It didn't. He then put me through to a Senior Technician.

With Senior technician:

Pretty much the same as the first technician with these exceptions:

Tried disabling QoS

Tried setting the router with WEP instead of WPA (for some reason, it's easier to just try it than to argue sometimes)

Result: Same as before, connection goner when desktop powers down.

At this point the senior tech put me on hold for a few minutes and then came back and told me that "they had never seen a situation like this and they would have to do some work in the 'lab' on it. They'd call me back when they figured out something."

Still waiting on the call back.

So...
I went into the desktop's power settings and set the sleep time to "Never" and the customer has his internet connection because he never shuts down the desktop and he's happy as a clam.

But, obviously, I'm not happy with it.

So...

Next time I'm there (which should be in a week or so) I intend to:

Replace the cat5e from the router to the desktop with a known good one (I tested the one currently connected with a cable tester, but when you've done everything you can think of that makes sense, you start to try to cover the other things) If this shows no change then I'll:

Disconnect the cat5e completely from the desktop and setup the desktop to connect with a wireless USB dongle. If that setup works and survives shutdowns, I'm sure the customer would be thrilled to leave it that way. But I'll still try:

Putting a new NIC in a slot and seeing if a connection works persistently through it. If yes, I'll assume that his three month old Gateway has a problem with the ethernet port on the mobo. If it still continues to lose the connection at the router on shutdown, I'll boot it off of a Linux disk and see if the internet connection at the router survives that after a shutdown. If it does, I'll assume there's something in the desktop's Windows 7 setup that's flaking out the router. If it doesn't, I'll curse the whole way home and obsess about the whole thing some more.

Sorry to spam with this long, rambling post. I'm just frustrated and it helps me to vent by documenting my intentions here.

 

[anonymous Mac Tech]

get the mac address of the eth card on the computer originally set up with Comcast (I know that Comcast binds to the mac address)

This isn't the case with Comcast. Did you actually call Comcast and have to give them a MAC address for provisioning? The only reason you should ever need to do this is with a customer owned modem so they can add it to box file. Is the modem the customers modem or rented from Comast? Do you know if Comcast supplies their phone service through this modem? Do you know the make/model of the modem? Does the machine still lose its connection when you are bypassing the router? When the machine loses its connection, does it lose its ip address or go to a 169.254.x.x address or no ip at all?

 

[tech0007]

Router Losing Signal

usually when a router is losing its signal,its a sign the router is going or soon will be gone. the recent study shows routers are last 3 to 4 yrs due to being on 24 hrs a day and heat is usually the culprit.


tech0007