[lug] Comcast users (OT)

Andrew J Jenkins andrew at winston.homelinux.org
Thu Jun 26 21:39:12 MDT 2003

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)
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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'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.

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