nanog mailing list archives

Re: Comcast Static IP Changed With New Modem?


From: Rafael Possamai <rafael () gav ufsc br>
Date: Wed, 11 Feb 2015 12:27:36 -0600

I've had a similar mistake happen with TWC. It's most likely a glitch in
their config system which should use the gateway's mac address in order to
assign a static IP on the docsis modem. Tech support should figure this out
pretty quick without escalating it much further. I've had an instance where
a second line/modem was added with the same gateway IP, and that brought us
down for over a day until they got around to fixing it.

My suggestions is to always keep your gateways/edges monitored with a
service like Monitis. I use ping monitors every single minute from three
different locations in the US (abroad available too) and get email/SMS/call
whenever something fails once, twice, etc from one, two or more locations.
Really cool monitoring system.

Hope this helps.



On Mon, Feb 9, 2015 at 10:32 AM, Justin Krejci <JKrejci () usinternet com>
wrote:

Has anyone run into the situation where their static IP address from
Comcast (on the business class cable modem Internet service) was changed
when the modem was replaced?

We have a remote site that uses Comcast as a backup Internet connection
and when we went to use it recently our VPN tunnel would not establish.
After working with the Comcast support group we discovered Comcast changed
our static IP address. I am working through trying to figure out the when
and the why with Comcast still and suspect it was changed when the modem
was replaced back in December. The modem was replaced by Comcast as our
previous modem was apparently EOL'ed.

We're now setting up additional monitoring to verify the accessibility of
our remote site via the Comcast connection so we don't have any future
uh-ohs when we need to use our backup connection and it too is not fully
functional.

TIA,
-Justin



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