Tech Support > Computer Hardware > Modems > Problem with cable modem and Win XP moving from comcast to new ISP
Problem with cable modem and Win XP moving from comcast to new ISP
Posted by Benrand on September 15th, 2006


Have a strange problem that seems to reside with the users XP config.

User machines: will pull DHCP IP on wired ethernet (Cisco sw, Foundry
rtr), will NOT pull DHCP IP on MTL Surfboard cable modem when running
WinXP, but will when FreeBSD is patrially installed from CD.

Looked at packet traces and the DHCP packets look fine, but her
machine doesn't seem to be recognized by the cable modem. The DHCP
transaction starts with her machine, but there is no response. Her
driver reports no pakcets recieved. Even placed a linksys rtr in
between and still see the same problem. Other laptops seem fine, work
with no problems.

Anyone hear of a user having issues moving from CM ISPs and
interoperability issues from some piece of software installed?

Someone mentioned this to me, but having trouble finding right result
from google.

Posted by Bit Twister on September 15th, 2006


On Fri, 15 Sep 2006 09:13:54 -0400, Benrand wrote:
You description sounds different but the
usual problem is cable modem will not talk to anyone else execpt the
mac seen on powerup. If it were me,
I would
o verify doze box is set to get dhcp,
o power all equipment down, including cable modem
o wait for one minute by your watch,
o power up cable modem and wait for leds to settle down to about normal
o power up the equipment on the wire from the cable modem
o then power up any remaining equipment.

Posted by Benrand on September 18th, 2006


On Fri, 15 Sep 2006 10:21:25 -0500, Bit Twister
<BitTwister@mouse-potato.com> wrote:


Thanks for the reply, been through it more than a few times.



Posted by Benrand on September 18th, 2006


On Fri, 15 Sep 2006 10:21:25 -0500, Bit Twister
<BitTwister@mouse-potato.com> wrote:


Well, I just found it. There was a QoS protocol enabled on her driver,
802.1p, that, I guess, the regular wired ethernet network didn't care
about but our cmts did.

Was a head scratcher.