[lug] Comcast users (OT)

D. Stimits stimits at attbi.com
Thu Jun 26 21:50:22 MDT 2003

Andrew J Jenkins wrote:

> D. Stimits wrote:
> > Jeff wrote:
> >
> >> Any Comcast users out there?  Have any of you notice a significant
> >> degradation in speed that last few days?  I'm still using the AT&T part
> >> of the network.  I haven't been migrated yet...
> >>
> >> Thanks,
> >> Jeff
> >>
> > There has been a long-term failure in the Longmont area (I'm under
> > attbi.com so far, it will become comcast.net in a couple of days).
> > These failures occur only at night, and it starts by losing the
> > ability to renew a DHCP lease. Dotted decimal addresses work for a
> > while (DNS dies too), but soon degrade to up to 85% packet loss. This
> > self-repairs late at night also, sometimes within a minute of the
> > failure, sometimes not for an hour or so. I have talked to the tech
> > people almost every night now for two months, and had a tech out at
> > the house. Result was that lines and equipment here are good. Last
> > night they found that one gateway was saying the cable modem was
> > online, yet the gateway had an 80% packet loss on one test board, and
> > showed as good on another. Just a few minutes before this, it had
> > failed and self-fixed itself, and the tech at that time said the line
> > quality was as good as they could get...yet less than an hour later,
> > it did it again.
> >
> > The tech that came to the house said no overt failures had been
> > noticed, but a series of people in the Longmont area that were gamers
> > were complaining about sudden latency increases and quality loss (this
> > was only at night, and coincidentally, only during maintenance
> > cycles). But because all of these reports happen at night when techs
> > are not available, and because techs work on it the next day, the
> > problem is not visible to them. This has gone on over two months now,
> > and at least one idiot said it had to be my hardware (despite the tech
> > coming out and telling me it is 100% good here).
> >
> > Were your degradations in speed at evening/night?
> >
> > D. Stimits, stimits AT attbi DOT com
> > (about to become a comcast DOT net)
> >
> > _______________________________________________
> > Web Page:  http://lug.boulder.co.us
> > Mailing List: http://lists.lug.boulder.co.us/mailman/listinfo/lug
> > Join us on IRC: lug.boulder.co.us port=6667 channel=#colug
> >
> >
> I'll add my own comcast story.  I'm in the boulder area, near 28th and
> Colorado.  I'm also on attbi.com, even though I installed in mid-April,
> 2003.  When I used to have 3 or 4 computers un-firewalled connected via
> switch to the modem, we'd all get DHCP, but if I rebooted one computer,
> the modem would stop renewing DHCP on any computer and also not give a
> new DHCP to the rebooted one.  Powering off the modem for 5 minutes
> fixed it most of the time.  When it was in a funk, manually assigning
> the IPs to what was DHCP-leased would work sometimes, sometimes not.
> I also experienced the "gamer-latency" problem intermittently, at night,
> but that could just as well have been traffic.

I've been using the attbi service since around September 2002. It worked 
perfectly until some time after Comcast took over. Around May 2003, it 
started doing this. And it was not during a reboot of any machine, it 
does this randomly at night to existing machines not trying to renew. 
Static IP only means that packet loss of 66%+ has to be tolerated, that 
DNS is gone, and that cycling the modem results in loss of carrier until 
it fixes itself; not cycling the modem means it self-fixes anywhere from 
a few minutes to a few hours later. The tests from the trouble phone 
number people say that they are getting conflicting reports. One 
software package says it is fine, the other says a gateway can't see the 
modem. If their own software can't agree whether it is online or not 
something is wrong. One particular gateway keeps showing up, but Comcast 
fails to send anyone out at night when it actually happens. By the time 
they get to the facility, the problem is gone. I don't think Comcast is 
sufficiently quality oriented to do what is necessary to track down an 
intermittent problem when not enough people complain about it. Their 
trouble board that indicates failures is obviously not enough, if one 
application shows a gateway/modem connected correctly, while the other 
says it isn't.

D. Stimits, stimits AT attbi DOT com

> I'm not sure if this is their DNS or my NIS (even though nsswitch.conf
> has dns: files dns nis), but recently I think DNS has been dying - it'll
> take a while (2s) to do the "Resolving Host" in Mozilla, but then
> near-instantly load the page.
> Go figure.
> _______________________________________________
> Web Page:  http://lug.boulder.co.us
> Mailing List: http://lists.lug.boulder.co.us/mailman/listinfo/lug
> Join us on IRC: lug.boulder.co.us port=6667 channel=#colug

More information about the LUG mailing list