[SATLUG] OT: Router-related question

Alan Lesmerises alesmerises at satx.rr.com
Tue Feb 9 22:09:28 CST 2010

John Pappas wrote:
> On Tue, Feb 9, 2010 at 05:48, Borries Demeler
> <demeler at biochem.uthscsa.edu>wrote:
>>> So I have 2 basic questions -- (1) Does anyone have any idea why this
>>> problem might be occurring, and (2)
>> Al, this is hard to say, it could be the cable modem, or it could be the
>> router.
> When I had this problem, the "visible" symptom to the (L2) tech was
> "flapping" due to incorrect signal strength.  Ask them for the operating
> characteristics of your line (line dbi or signal strength particularly) as
> that can isolate a weak cable or splitter.
I did recently have some trouble that was related to signal strength, 
and the tech replaced something in the junction box at the end of the 
block, but I didn't catch the specifics.  It seemed to correct the 
problem at the time, though.
>>> is there a command or something that I can send to the router to have it
>>> reset itself without having to manually power it down/up?
> DDWRT can cron a reboot, but not sure that you can "conditionally reset"
> based on loss of connectivity.
> The corrective action that "fixes" it is a router reset?  Does the WAN port
> IP change when reset?  Often, if the modem cycles the connection the router
> will loose connection, even though it shouldn't.
Powering down then turning it back on (after ~10-15 secs) will 
re-establish my Internet connection nearly every time.  There have been 
a couple of instances where the cable modem didn't seem to get a signal, 
but that appears to have been a different issue.
> If this solves your problem, then most likely this is a TWC or a cable modem
>> issue and you need to talk to them to either fix their network or give you
>> a new modem.
> The correction in my case was 2 fold: replace the modem, and then replace
> both trunk and modem line by running a new, direct line from demarc to modem
> location, with the following splitter config:  2 way from trunk-TV, modem,
> and a 4way for TVs.  I am sure a 6 or 8 way could have been used instead,
> but linemen aren't usually packing them, so he used a 2+4 config.
> If the tech can isolate a signal issue, they will have you replace the modem
> first (as they have to do no work to do that) and then if that does not
> "fix", they will send a lineman to fix the line.
> HTH,
> John
Sounds like I'll need to check out the cables as I'm doing the 
troubleshooting.  Thanks.

Al Lesmerises

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