Sat, 31 Oct 2009

Adventures with Comcast: Part ohnoesnotanotherone in an ongoing series

Regular readers of this blog (yes, both of you!) may remember the computer/broadband/ directory that this post appears in as the collection of my Comcastic (yeah right) experiences with my ISP.

But I think this week may top everything. I'll just try to jot down some notes before I forget all the gory details:

  • On Tuesday, I edited one of the internal nvram configuration variables of my trusted wrt54g router in order to add the older daughter's shiny new iPod Touch to the set of 'permitted' MAC addresses. This router, running a custom Linux variant called OpenWRT had essentially not been upgraded since I first installed it, and still required a quick reboots after updating of configuration values. However, that worked fairly flawelessly for 4 1/2 years. Until Tuesday.
  • Upon reboot, I got what appeared to be an invalid network setup from the cable modem. IP and Gateway assigned , but no DNS and no ability to ping anywhere. Crap. So I fiddled with this all evening, including a service call to Comcast but to no avail. When a laptop was directly plugged into the cable modem, it got correct settings albeit on a completely different subnet. So for the next day, we left one machine directly plugged so that my wife could at least telecommute.
  • Somehow it became apparent that waiting insanely long for the router to remain powered-down -- and we're talking five minutes or longer -- helped. So by now we were suspecting the cable modem. I use a standard Motorola SB5101 I once had to buy in a rush because of the Comcastic ones who all of a sudden changed their minimum requirements which meant they would no longer connect to my existing modem. Anyway. So on Wednesday I called Motorola and had a decent service call with them but as I was at work I couldn't follow up with part numbers etc pp. At least I learned that I seem to have two months of the two-year warranty left...
  • So by Wednesday evening I decided to fall back to the really cheap and old Speedstream router I had used before the Linksys wrt54g. That worked, albeit sloooooowly. Wired and wireless ethernet, direct assignment from the cable modem. All well. But did I mention it was sloooow though?
  • Thursday evening was skipped as I was at the Chicago R meeting we organize to complement our R / Finance conferences in the spring.
  • Given that the cable modem worked with the old Speedstream and with directly-connected machines, I decided to finally go for a long overdue update of the wrt54g software. So that happened on Friday, i.e. yesterday. And similar to my previous wrt54g notes, I needed to flash the new software with the tftp protocol and a helper script on a laptop connected to the router. All this took a while as I needed to remember to also send to a ping flood to the router to be able to catch the tftp request, needed to test which of the atftp and tftp binaries worked reliably, and whether the router prefers .bin images over .trx images when using the tftp protocol. But lo and behold this worked, and I configured a shiny new Kamikaze aka 8.09.1 version of OpenWRT. This even connected to the cable modem once I helped with DNS entries. OpenWRT generally rocks, and this new release is a lot nice than the more bare-bones version I used to run.
  • Unfortunately, I had picked the bcrm47xx variant -- the 2.6.* kernel version of the OpenWRT Project's software for my WRT device. And guess what, that one does not include wireless support due to issues with Broadcom drivers and the kernel. Grrr. So once I had that confirmed this morning, I quickly switched to the bcrm-2.4 variant of the same 8.09.1 release. At least now I can flash from within using the mtd command from the commandline.
  • But once up and running with the bcrm-2.4 release, I ran into the same issue we have had with the Motorola cable modem and Comcast behind them. Each time I connect with the wrt54g, I end up on a specific subnet, without DNS and with no ability to connect. The Speedstream still worked. So what to do? Well, MAC Cloning to the rescue. Now the Linksys wrt54g pretends to be the Speedstream, and all, at last, is well again.
  • So after four days of intermittent service, which means that my few web pages, blog, and goodies like CRANberries were invisible, I now have better router software. That could have come a little easier, and I still don't quite know why Comcast decides to no longer service the wrt54g under the MAC address it presented itself with for 4 1/2 years. I have paid thousands of dollars over that time to get broadband access. But this, I don't quite call service. To top it all off, guess who cold-called to sell VOIP service while I wrote this up? Oh, it's Comcastic ...

/computers/broadband | permanent link

Thu, 05 Jun 2008

Adventures with Comcast: Part ohbynowIhavelostcount in an ongoing series

Regular readers of this blog (ed: oxymoron alert) may recall tales of woe with our beloved (ha!) cable internet provider such as this; then there are of course minor tales like this or this or this or the other stories on on this page but I am probably forgetting others.

Anyway, yesterday's highlight was initiated with a mail, seemingly sent to all customers, informing me that

ACTION REQUIRED: Comcast has determined that your computer(s) have been used to send unsolicited email ("spam"), which is generally an indicator of a virus. For your own protection and that of other Comcast customers, we have taken steps to prevent further transmission of spam from your computer(s).
and the email went on to recommend some Windows anti-spam measures, including a reference to a page I could only open with IE at work and one URL to a page that doesn't exist. Nice. Not. Needless to say, there are now Windows computers sending mail (via Comcast) here (as the lone windows box, my wife's work laptop goes straight to her university webmail).

And obviously, they blocked port 25, so no more mail sending from home. So I grumpily logged a compaint having been on hold and in telephony menu hell for fifteen or twenty minutes. I was promised to hear back in 72 hours. Hasn't happened yet, naturally, but we're only half way through...

Anyway, to make a long story short and this post constructive: Here is what you do on a Debian or Ubuntu system running exim as your mail transport:

  • sudo editor /etc/exim4/conf.d/transport/30_exim4-config_remote_smtp_smarthost and add a line port = submission in the remote_smtp_smarthost block (assumming you have the split configuration chosen for the exim4-config package). Setting port to 'submission' switches from plain old STMP to the authenticated version running on port 587; submission is mapped to 587 in /etc/services.
  • sudo editor /etc/exim4/passwd.client and add your user and password id as e.g. for comcast web-login
  • sudo update-exim4.conf to update the configuration
  • sudo /etc/init.d/exim4 restart to restart exim
And it may pay to check /var/log/exim4/mainlog for any irregularities. Barring those, you should now be sending mail to you smarthost using authenticated transfer over port 587.

In the meantime, it looks like they unblocked port 25 at some point today...

/computers/broadband | permanent link

Thu, 27 Dec 2007

Internet NON-Service Provider: Yet another Comcast saga

About a week ago, our internet connection appears to have dropped around midnight. Not a biggie, one thinks. So on Friday morning between shower, breakfast, and leaving for work, I power-cycled the cable modem and router a few times which 'usually' helps.

Not this time. Still no signal by the afternoon, and when Lisa called the help line, they confirmed that they could not see our cable modem. That could have given it away, but I didn't click.

This being this time of year, we were actually out overnight on Friday so that I couldn't get to inspect matters at home. Also, friends and neighbours were out the next day so I couldn't get my hands on another cable modem to see if it was the line (my suspicion at the time) or the modem. All I could do was call, go once more over all possibilities with the tier-1 help person -- and schedule a technician to swing by on Monday afternoon, i.e. on Christmas Eve, or about 48 hours later (!!). So I made do over the weekend with two trips to the local library to consume some of their wireless signal to catch up on things.

The big surprise came on Monday. The technician, was on time and rather friendly and knowledgeable, checked the signal strength at the box outside, and on two cable outlets in the house. All fairly well. So during the second call to Comcast, we turned our attention to the cable modem. A few years ago I returned the 'leased' modem and bought an inexpensive 3com cable modem. Only after checking that it was supported, of course.

Well now it seems that Comcast decided that this (old) modem can only talk Docsys 1.0. And instead of telling me in advance, they just fscking dropped it cold. Unbefriggable. I must be getting two fliers a month informing me how great Comcast's so-called (and IMHO rather overpriced) 'Triple Play' is. You'd think that they use that mail-out infrastructure to let me know about the service change. Or use email, after all they are my ISP. Naaah. Rather just drop the service cold right before the holidays. That's the spirit.

To clarify and repeat, I do not mind service updates. I do not mind improving standards and improved throughput. And as I am quite happy to buy a new modem on the spot on Tuesday afternoon -- yes, Christmas eve, because I then have nothing better to do than to troll in the mall to buy a new Motorola cable modem at full retail cost rather than somewhat more cheaply at Amazon or other places -- I could easily have done better if only they had told me in advance. I could go and use some choice terms , but as we're still in the holiday season I better stop... Maybe I should just go back to DSL and save a few bucks.

/computers/broadband | permanent link

Wed, 17 Jan 2007

New ip

In the middle of last night, Comcast once again decided to move 'us' (and presumably gazillion others) to a new IP address. In the process we moved from the 24.14.* subnet back to 67.174.*.*.* subnet.

For once, I didn't seem to have blogged about the last chance but it feels like the previous assignment had held up forever, i.e. a couple of months. Thanks to the good and quick dns service at Gandi, my two domains and were again visible within minutes of me finally noticing the chance this morning. Sorry for any service interruptions in the meantime.

/computers/broadband | permanent link

Thu, 07 Sep 2006

More Comcast fun

One of the many recurring themes on this blog is the amount of trouble we're having with Comcast. So Ladies and Gentlemen, here is a new one:

Having been forced to use the ISP as a smarthost for delivery (as reverse lookup is not provided for residential service), I depend on Comcast to deliver my mail. But look what we just got for attempting help a user on the quantlib-users list:

Reporting-MTA: dns;
Arrival-Date: 8 Sep 2006 1:46:30 +0000

Final-Recipient: rfc822;
Action: failed
Status: 5.1.0 MAIL FROM: 550 REPLY:
Diagnostic-Code: smtp; Permanent Failure: Other address status
Last-Attempt-Date: Fri, 8 Sep 2006 01:46:36 -0000

So a benefit of handing over around $500 per annum is that I do not get my mail delivered because the goods folks at now think ATT Broadband aka Comcast [ to whom the address mail server resolves ] is a spammer.

Someone please remind me why I haven't switched to Speakeasy?

/computers/broadband | permanent link

Tue, 03 May 2005

And another new IP address

Broken record alert: As previously noted on these pages, Comcast now stresses dynamic in dynamic IP addresses. The last one lasted three weeks and flipped on Saturday. As this changes the dynamics of using broadband for a few personal projects, I may have to look into more expensive options (Speakeasy?) or external hosting.

/computers/broadband | permanent link

Sat, 09 Apr 2005

And more new IP addresses

As this has become a standard feature around here, I should mention that we did of course get two new IP addresses in the aforementioned switchover to the new gateway. As this required an interim solution with the older 802.11b gateway, I presume that two new MAC addresses at the receiving end leads to two new IP addresses.

Only that we ended up getting three in 24 hours. I still suspect that Comcast may not keep these around for seven to eight months as they used to. Time to host my few pages (principally Quantian) elsewhere? Suggestions welcome.

/computers/broadband | permanent link

Wed, 16 Mar 2005

Blimey, this is getting annoying

As mentioned yesterday morning and yesterday evening, the ISP powers-that-be at the company (whose name I shall not speak for fear of further upsetting those very powers) rotated our IP address once more. And just like yesterday, to provide the full service experience, service also fell off which resulted in another nice eight hour outage. The total must now be north of twenty hours of interrupted service over the last 48 hours. Yuck.

Again, apologies to everybody who tried to connect here lately -- this is unfortunately beyong my control. Traffic back up, DNS has been updated, fingers are crossed as well. Maybe this time it'll work.

/computers/broadband | permanent link

Tue, 15 Mar 2005

Grrrnnnnlll ... those clowns at Comcast!

As I blogged this morning before heading to work, Comcast rotated our IP address in the middle of the night. What I didn't mention, and what looked fishy, was that they placed us onto a completely different address block.

And lo and behold, while I was at work, everything dropped once again leading to an eight hour outage. We're back now, on the previously used network address block, in hopes of sticking with this new address for the usual nine month. DNS et al have been updated for the main address but I still need to update the address.

Apologies to everybody who tried to connect in the interim, but this is unfortunately beyong my control.

/computers/broadband | permanent link

Once again an IP change from comcast

Well, following the previously blogged changes in March 2003, December 2003 and August 2004, we were once again moved to a new IP address by Comcast.

Having updated the DNS entry, and thanks to quick redirection at Gandi, web traffic is already back. If you're on cached DNS data, it should get reflected "soon" too.

/computers/broadband | permanent link

Fri, 19 Nov 2004


Service really has been dropping, as noted most recently in this entry from October. Today it dropped around 10:00am, and didn't come back until I got home. Power-cycling the modem didn't help, so I called Comcast and obtained a reasonably clueful and patient service rep. I dodged the question whether I have a router, manically flipped cables and stuck the windows laptop from work back in. The service did in fact come back once that machine started making request. I have to try explict dhcp re-lease request from the Linux gateway next time.

The rep recommended getting another broadband router -- replacing this cheap 3com CM29220 I aquired via with a Motorola 5100 or 5120. Any opinions on that?

Anyway, sincere apologies to anybody who may have tried to look for Quantian or this blog.

/computers/broadband | permanent link

Tue, 26 Oct 2004

Quality of service. Sort of. Maybe.

A few days ago, I had been pondering how the Comcast service had been remarkedly trouble-free over the preceding weeks. Well, and sure enough, that thought alone must have brought on the evil gremlins as we appear to have been off the web for several hour last night, as well as for most of the morning until around 2pm local time -- as is pretty easy to check from the various server logs, in particular smtm and http.

To those have tried to access these pages, or the Quantian ones, my heartfelt apologies. The best I can offer for such time would be ... the Google cache. Sorry for any inconcenience. One day I may look into real hosting, in the meantime this will have to do, in particular as the last few gripes are all from over a year ago.

/computers/broadband | permanent link

Thu, 05 Aug 2004

And another new IP :-/

Now for the first time since December 2003, and following the March 2003 change, which itself suggests a nine-month pattern, Comcast assigned us a new IP address.

So I just edited the web form at gandi for the DNS of the .com address, sent a signed email to the 'change' bot at for the .net address, edited the configuration for bind, edited /etc/hosts, edited apache's httpd.config, and updated the IP address itself for the mail forwarder. Now all I need to do is wait for DNS to catch up :-/

Somewhat of a silly game, really. Maybe I should splurge for a real provider like Speakeasy?

/computers/broadband | permanent link

Fri, 09 Jul 2004

YANCC (Yet another nice Cringely column)

Robert Cringely has another neat column on broadband exploits. He's singing the praises of a $99 router device to get redundant dsl and cable modem service. I had wondered about that too, doing it directly in a linux router/gateway box, but then I don't run a biz from home, but only a bandwidth consuming hobby or two.

The whole column is very refreshing for the dismissive tone of his SBC comments. Cringely is a much smarter geek that I'll ever be, and he overcame SBC in neat ways. I'll probably remain scarred from the long troubles we had getting service after we came to Illinois ...

/computers/broadband | permanent link

Wed, 17 Dec 2003

And another new IP :-/

For the first time since March, Comcast assigned us a new IP address. DNS entries, bind, /etc/hosts, apache config, ... have been updated, as has the apache configuration. Let's see how long we can keep this one.

/computers/broadband | permanent link

Tue, 22 Jul 2003

Comcast ...

Went out again last night, somewhere between 01:30 and 02:00. Was off when I went running at 05:30 and is still down now at 06:20. Darn.

/computers/broadband | permanent link

Sat, 19 Jul 2003

Out for the count ...

Just back from ten wonderful days in Colorado, and it looks like my gateway / firewall / web server went down on July 17 around 04:30. Have yet to find a reason in the logfiles, but the cable modem also needed a cold reset. For what it is worth, the other machines on the home network were fine. Anyway, I am back, the gateway is back up. My sincere apologies if you had come here in the last three and a half days.

/computers/broadband | permanent link

Tue, 10 Jun 2003

Down and out provides a decent service, but I wish it wasn't going down as often during the nightime. Given that quantian gets pretty regular traffic, I can pinpoint outages fairly closely. An entire night last week, and a good three hours last night. I guess you can't ask for more when you only spend fourty-some dollars.

/computers/broadband | permanent link

Wed, 30 Apr 2003

Cable really is TV too

One fringe benefit of having broadband internet is that the cable is, well, cable. Invested in a cheap TV capture card (ATI All-in-Wonder Radeon), went to Radio Shack and bought a cable splitter and two short cables -- that's it. Installed avview (which was already a Debian package) along with the binary only ati.2 drivers from gatos, configured sound to use Alsa --- and am now enjoying TV under X11. Not bad.

/computers/broadband | permanent link

Thu, 27 Mar 2003


It would of course have helped if I had adjusted bind and apache right away. Next time I may remember... We apologize for any inconvenience caused.

/computers/broadband | permanent link

New IP :-/

Ah, the joys of DHCP and 'almost fixed, but not guaranteed to be static' IP allocation. Appears that we got a new one last night, for the first time in about five weeks.

If only DSL providers weren't so low quality, and greedy. But for now I think I rather stay on cable. We'll see.

/computers/broadband | permanent link

Sat, 15 Mar 2003

Dns points back at us

Just changed the dns entry, the * machines should soon be served again from here.

/computers/broadband | permanent link

Mon, 24 Feb 2003

Well, it took "only" five visits ...

by (generally friendly) ATT cable guys to finally get the house connected with fresh wiring from the pole. Et voila: looks like we now have service.

Too bad it took exactly four weeks, the aforementioned total of five visits and I don't-want-to-remember-how-many phone calls to their (generally also very friendly) call centers. But I will supposedly get a month credited.

Well, at long last we appear to be re-connected so I shouldn't gripe. And it is faster than DSL. Telocity may now rest in hell. Anybody care for a DSL modem? :-/

/computers/broadband | permanent link