Adventures with Comcast: Part ohnoesnotanotherone in an ongoing series

October 31, 2009

(This article was first published on Thinking inside the box , and kindly contributed to R-bloggers)

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
    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
  • 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 …

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