[shifuimam]

I'm having a hell of a time trying to troubleshoot this issue.

My mother has SBC/AT&T DSL. They sent her one of those little Speedstream modems that has a semi-router built in (it assigns a 192.168.0.xx IP to whatever is attached to it, but passes AT&T's 72.xx.xx.xx DNS IPs transparently). I set her up with a Belkin wireless 802.11g router that, incidentally, I used on my own DSL connection (same model of modem) for two years without a hitch. Before I gave her this router, she was using an old POS D-Link 802.11b router.

She will randomly be unable to get on the Internet. If you type an address into Firefox and hit enter, it times out. But, I can ping anything I want, except the router (192.168.0.1). I can ping Google and get a response, I can ping DNS IPs I know exist (specifically, my alma mater's two DNS, which I have memorized from doing network tech support there for two years...sad, I know), etc. Not only that, but she uses the Google Talk client, and it pops up notifications when she has new mail in her Gmail account. If she clicks on the notification, it opens up Firefox and immediately takes her to mail.google.com...but she can't open up Firefox herself and type www.gmail.com and get to it.

Thus far, the only thing I have found that fixes this is to restart her router, which resets the connection between the router and the modem, which fixes the problem. She's "fixed" it before by unplugging the router from the modem and plugging her computer directly into the modem - which also resets the connection, which fixes the problem. She's never on the Internet at home long enough to see if she's getting this same weird issue when she's directly connected to the router.

Anyone here on AT&T DSL? Have you seen this problem before? This is driving me crazy. I suspect something is amiss with her modem, because as I previously mentioned, I used this exact router on my own DSL modem without it ever crapping out on me. She had the same problem with the D-Link router, but I chalked that up to being a crappy router. Now, I'm not so sure that it was the fault of the router.

[nonhuman]

It could be a problem in her wiring. I currently have my (Verizon) DSL modem hooked up to a phone jack in the kitchen where it works fine (mostly). I had tried hooking it up to a phone jack in the bedroom, but due to a shitty wiring job by previous occupants the modem couldn't maintain a connection for more than a couple minutes.

I would see if AT&T will replace the modem for free. If not, since you have the same one, maybe you could try using yours at her house and see if that works (assuming you haven't since stopped using AT&T DSL and gotten rid of it). Of course I'm also assuming you live anywhere near your mom... If not maybe you could convince her to leave the computer directly connected to the modem for long enough to see if the problem persists.

Regardless, I'd agree with your assessment that the problem is unlikely to be with the router or computer, and that the modem and/or wiring is the likely culprit.

[Big Mac]

I have AT&T and the same modem. How are you handling PPPoE? On the modem or on the router? You'll get more reliable connections if you turn off the modem's PPPoE and turn on the router's PPPoE.

[shifuimam]

Crap, I didn't even think about the wiring. She lives in a house built in the 1920s, and it's got a lot of original wiring in it. The phone jacks have all been upgraded to the standard RJ-11, but I wouldn't be surprised if that was part of the problem.

I was thinking about trading out modems, anyhow - I'm still on DSL, and we live in the same city. The thing with the computer is that she doesn't leave her computer on. The router is on all the time, so it has a chance to drop the connection, whereas the computer is only on for a few minutes to an hour at a time.

Thanks for the insight though - I'll give those things a shot.

[shifuimam]

Originally Posted by Big Mac 

I have AT&T and the same modem. How are you handling PPPoE? On the modem or on the router? You'll get more reliable connections if you turn off the modem's PPPoE and turn on the router's PPPoE.

I may need some more details on that - all I've done on her DSL and mine is plug in the router, logon to the modem (192.168.0.1) and click the link to connect to the Internet (which requires putting in that access code), and go. Is there a different way I could set this up?

And does this explain why the hell I can ping IPs but not actually access anything in the browser?

[MrNo]

You could enter the DNS address manually or you could try to switch the PPoE connection to the router instead of the modem.
The DNS address can be found on the modem's settings page.

[Cold Warrior]

one or two people here recently, also with DSL connectivity issues, had success reducing their MTU from 1500 to 1200 or something.

[ghporter]

MTU with DSL is critical for reliable, speedy connections. The PPPoE protocol takes up at least 8 bytes of the datagram, so the MTU for any PPPoE connection cannot be greater than 1492. If that doesn't speed up the connection, drop it down by 8 more and try again.

But changing the MTU won't fix this problem; it will only correct horrible download speeds and timeouts. This one sounds like a possible problem with the modem's PPPoE setup. I'd go with changing the modem to just bridge from the DSL line to Ethernet, and then set up the router to handle PPPoE. If that doesn't fix it, it'll at least provide more flexibility and easier control.

[Big Mac]

Well that's interesting. When I have a modem connected I can no longer access the modem's configuration page. Are you sure you have the modem and computers connecting to the router? Anyway, when you log into the modem there should be a Connection link or something similar (it's been a while since I did it). When you get to the PPPoE setup portion, there will be around four different options. You want the one that allows you to turn off PPPoE built into the modem. Then you go to the router configuration page and enter your PPPoE connection information.