Problem with Router and Desktop's NIC

[CityK]

Before I went on vacation, I unplugged all non essential electricals, including computer stuff ...however, I forgot to disconnect the actual cable line from the modem.

The connection topology is as follows: big bad internet --> cable modem --> router ---> wired connection to desktop and wireless devices (lapto, cell, ...).

Upon return home, when I plugged everything back in (and all devices powered on as per usual), I was unable to connect to the internet on any device (all indicated that there was no internet connection ... all indicated being connected to the router (i.e. both wired and wireless connections to the router seemed to be fine).

My initial thought was with the cable modem. I both rebooted it and pin reset it. No change resulted.

So my attention switched to the router. Bypassing the middleman, I first connected the cable modem directly to the laptop via the lan cable. Successful connection to the internet! So it seemed like I was on track.

Next came a straight line test from the modem to the desktop. Negative. Hmmmm....not a straight forward problem afterall.

I swapped cables but no luck. Tested the direct laptop to modem connection with all cables, and it works properly in every case.

So something is wrong with the chain between the modem and router and desktop (as well as in the case between the modem and straight to the desktop). However, I can successfully ping or even access the modem's diagnostic page from the desktop (whether with a straight line connection to the modem or with going through connected to the router). I just can't get any internet connection from the modem to the router or straight to the desktop to work.

I'm thinking that maybe there was a surge on the cable line (there was indeed lots of thunderstorms apparently while I was away) and the line into the router and terminus pt at the desktop's NIC took a hit. But I don't know ... I don't smell anything fried (though it could have happened weeks ago) nor do I see anything wrong, and, as indicated above, the equipment is working fine in all other respects... I just can't get an internet signal/connection to them from the modem.

Anyone have any thoughts/recommendations/similar experience?

I'll likely throw money at the problem if I can't figure it out soon enough.

(I do find it amusing though that, if the problem is due to lightening, my very intention and actions to protect from the likes of such (as well as preventing the needless waste of electricity) by unplugging the devices was undone by leaving the cable line attached to the modem ... and any surge would likely have been grounded properly had I kept them plugged in and left the stupid power on in the first place).

 

[CityK]

I'll add that I don't know what the pin assignments are on the cabling ... is there a lone wire in the pairs that carries "internet" signal? Again, in all other regards that I can see, the cabling and devices are working fine .... its just the blasted outside world signal for the interent.

 

[jtr1962]

Just a shot in the dark but try letting the cable router and modem sit overnight unplugged. Sometimes that works on electronic equipment when all else fails.

 

[Stereodude]

Are you sure your cable modem doesn't lock access to a particular MAC address? I remember early on in the broadband days you would have to clone the MAC address of your PC (that you setup the cable modem with) into your router to make it work.

 

[CityK]

Just a shot in the dark but try letting the cable router and modem sit overnight unplugged. Sometimes that works on electronic equipment when all else fails.

Its worth a shot ... maybe there is even a freezer trick for modems and routers like there is for hard drives LOL.

 

[CityK]

Are you sure your cable modem doesn't lock access to a particular MAC address? I remember early on in the broadband days you would have to clone the MAC address of your PC (that you setup the cable modem with) into your router to make it work.

I thought about that, and there is actually an entry on the modem's diagnostic page that mentions something about number of computer connections allowed being two. But I don't think that is the case -- the desktop is the original device that the modem would have been accessed with ... unless pin resetting has overruled that ... but then again, I've done that before, and have had straight cable connections to other systems (i.e. different MACs) and never had a problem ... so I don't think its a case of it (modem) being married to a particular MAC.

But then again, a related thought that I've had is whether something has been set via the provider once power on the modem was re-established after being off for a couple of weeks. So I might have to call them to see if they lock access to a device if there has been no activity on the line for a certain period of time.

 

[timwhit]

Just buy your own modem and hook it up.

 

[CityK]

Just buy your own modem and hook it up.

The modem is already mine ... I think I originally purchased one from the ISP (it was a good price) about seven or eight years ago. Then the network had a speed/DOCSIS upgrade and the modem needed swapping to a newer model, which the ISP provided for free to me. They're actually a good provider, but they rely on a big bad provider for the last mile to the home.

Anyway, the problem is solved as jtr's suggestion did the trick!!! All devices (wired and wireless) are now able to access the internet.

I guess a register bit had become stuck and clearing the charge released it again to the correct setting.

 

[jtr1962]

Indeed, sounds like a stuck register or something. Glad my suggestion fixed it.

I had a similar problem a month ago. One of my A/Cs was clogged, the water wasn't draining outside. Pulled it out and cleaned it. When I put it back in the control panel gave a F0 error code. Supposedly there was a key combo to reset it but a few keys on the pad haven't worked in years, so I couldn't do that. I was all ready to buy a new control panel and then I figured let it sit overnight unplugged. This was a really old microcontroller, probably didn't even have any non-volatile storage. I reasoned letting all the charge drain should restore the registers to their default state. It actually worked. I've used this "trick" on a few other devices as well.

 

[snowhiker]

If your modem and router eight years old verify that you are getting the up/download speeds you are paying for. My ISP upgraded me from 25 to 50 mbps months before I ever noticed because my old modem and router were limiting speeds. And if it's flaky enough to work after being allowed to "rest" for a day you might want to replace them anyways so they don't fail when you need to get on the net "oh-my-gawd RIGHT-NOW" to check/do something.