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lambition
join:2004-08-26
Oakton, VA

1 edit

lambition

Member

[VA] Anyone experiencing intermittent connection loss?

During the thunderstorm on Monday (June 9), I lost internnet connection and several digital channels.

The problem was fixed when the technician from COX came out about an hour later and did something in my back yard.
(I never called them, so they must have received call from someone else in the area or detected something was wrong with their equipment.)

However, since then I begin lossing internet connection at least once a day.
When I lose connection, cable light is solid green (as if it is working as it should), however I cannot get on the net or access the modem uisng 192.168.100.1.

To get back on the net, I have to reset the modem by power cycling.

I contacted COX and I was told there is no report of such problem in my area.

Are there anyone else having simillar problem?

Hope it is not my cable modem that went bad.
It was connected to a UPS and COX digital telephone equipment should have a surge protector built into it.

I called COX support and they said, they will charge $42 per hour if it turns out it is problem with anything inside my house.
daveinpoway
Premium Member
join:2006-07-03
Poway, CA

daveinpoway

Premium Member

Even though you had some power protection, nothing will save your equipment if a lightning strike is close enough.

In order to see if the modem is bad, you could rent one from Cox for a month ($10).

I believe that they will work on your internal wiring if you sign up for the wiring protection plan (not sure if this is the exact name)- $3 or $4/month.
lambition
join:2004-08-26
Oakton, VA

lambition

Member

The modem works fine when it is working.
Do you know if there is anyway to find out if it is modem lossing signal or modem freezing?

I know how to network and wire the house. I just don't have equipment to test.

Ikyuao
join:2007-02-26
Wichita, KS

Ikyuao

Member

You can request a tech people to come out but it cost you a money, just call cox to request.
lambition
join:2004-08-26
Oakton, VA

lambition

Member

I already have requested a tech to come out. But I'm worried it might be prolem inside my house (possible the modem it self.)

All other equipments (TV tunner, Cable Box, and TV) are working fine.
The Cable entering my house first goes into cox digital telephone equipment. Then the cable coming out of it goes to splitters.

I believe the telephone equipment has surge protector inside (a ground wire goes into it as well).

It may also be that telephone equipment that went bad, but since I don't use digital telephone from COX, I cannot test it.

Ikyuao
join:2007-02-26
Wichita, KS

4 edits

Ikyuao

Member

Click for full size
This nice cable coaxial tester :)
That only cable contractors people are carrying a testing equipment device. Your best bet is search on a net to purchase it a equipment sale for testing cable wiring. I found that nice cable tester device for cable wiring I can afford to purchase it via net. Go to purchase this device if you want
»www.hometech.com/tools/t ··· ID-33856
lambition
join:2004-08-26
Oakton, VA

2 edits

lambition

Member

If you are talking about regular cheap cable tester, that is no good in this case.

Those only tests if the cables are conducting. I know it is conducting just fine since it works, when I have no problem.

The kind of tester I'm talking about its the one that measures strength of the signal at various frequencies.

I doubt even that will help in my case since it is not always having problem. It is only causing problem once or twice a day.

I believe it is either some sort of noise coccuring on the cable system intermittently or something is cauing the modem to freeze.

--- Edit ---

The tester you posted only tests if the cable is conducting and wired correctly.
For coaxial, it can only test if it is conducting.
It cannot test if it has good over different frequencies.

Ikyuao
join:2007-02-26
Wichita, KS

Ikyuao

Member

Well, How do you testing cable coaxial? That is not possible unless you buy a cable tester device to test a cable wiring to see if it is good signal.
lambition
join:2004-08-26
Oakton, VA

lambition

Member

Exactly.

That is why I am unable to test it myself. Testing equipments that can actually test signal level over different frequency is very expensive.

Ikyuao
join:2007-02-26
Wichita, KS

Ikyuao

Member

Yeah, Viewing different frequencies is more expensive than this cheap cable tester device that most cable contractor are carrying a advanced tester device.
lambition
join:2004-08-26
Oakton, VA

lambition

Member

Click for full size
I'm getting good signal to my cable modem when it works.

This is pretty good signal to my knowledge.

I cannot check signal level when it does not work since I cannot even access that page when it does not work.

Ikyuao
join:2007-02-26
Wichita, KS

1 edit

Ikyuao

Member

Nicccceee, Dude that your Cable modem is DCM-202 that is D-link brand And also your signals are good to go. If you really concerned about cable wiring then I suggest that you take look at sample cable tester device items I provided you a http link.

ccc1005
join:2003-06-03
US

1 edit

ccc1005

Member

I was having an issue with an (apparently) bad IP address getting assigned (68.100.x.x) early last week. I power cycled and got back to the 72.x normal address. See what IP your router is getting when you lose the connection.

Ikyuao
join:2007-02-26
Wichita, KS

1 edit

Ikyuao

Member

Oh, I don't use router hardware. Linux gives me very useful iptables firewall incorporated in a Linux kernel and also I can write to add iptables script file of firewall modification. Also router hardware doesn't do auto TCP tune for TCP data buffer for keeping bandwidth at full and Linux do good job of keeping bandwidth at full flow of bigger pipe.
lambition
join:2004-08-26
Oakton, VA

lambition to ccc1005

Member

to ccc1005
I believe my IP address staied same. I will check to make sure when I lose connection again.

My router is a Linux (BrazilFW) on x86 computer.
lambition

lambition

Member

Ok. Ijust lost connection again about 4 min ago.

IP address stayed same.
Cable light was solid green.
Had to reset the modem to get back on the net.

Ikyuao
join:2007-02-26
Wichita, KS

Ikyuao

Member

Mmmm... Did you find any clue in your firewall iptables script file to allow state of related,established of incoming from internet?
lambition
join:2004-08-26
Oakton, VA

lambition

Member

I don't know anything about those.
I just use default script developers of BrazilFW wrote.

I bearly know how to use iptables. (just allowing and blocking traffic from certain computer/destination.)

Ikyuao
join:2007-02-26
Wichita, KS

4 edits

Ikyuao

Member

I see, I found somewhere on internet to show me to how to write a shell script file so I decide to try out to do automated script file to run from my saved firewall.conf file in /etc to /ect/network/if-up.d/firewall shell script file to run iptables that every time that any Ethernet link is up.

# Generated by iptables-save v1.3.6 on Sat Jun  7 15:48:48 2008
*filter
:INPUT DROP [3017:173484]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [1141:137870]
-A INPUT -i eth1 -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT -i eth2 -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT -i eth3 -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT -i eth4 -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT -i eth5 -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT -i eth6 -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT -i eth7 -m state --state RELATED,ESTABLISHED -j ACCEPT
COMMIT
# Completed on Sat Jun  7 15:48:48 2008
 
That is my iptables firewall script file.
#!/bin/bash
echo starting firewall...
iptables-restore < /etc/firewall.conf
 
That is my shell start up script file for iptables program.

Let's get back on topic about his cable intermittent connection issue.
lambition
join:2004-08-26
Oakton, VA

lambition

Member

NEW INFO.

I just lost interenet connection again.

I did serveral tests before resetting the modem.

When I change my IP address to static in the range of 192.168.100.x I am able to access configuration page with 192.168.100.1.

The modem was showing signal is good and locked. No errors at all.
However I was unable to access anywhere outside my home network.
DHCP client fails to get IP address from DHCP server. (no response from DHCP server)
ggrell
join:2003-03-29
North Kingstown, RI

ggrell to lambition

Member

to lambition
lambition, I'm actually seeing the exact same thing here in southern Herndon, VA. Modem is all green, blinking as if sending data, but I can't get to the internet. I've even taken my router out of the equation, connected desktop directly to cable modem, and still nothing, until I power cycle the modem. I have also noticed that several TV channels are showing intermittent bursts of static; I'm sure the two are related.
lambition
join:2004-08-26
Oakton, VA

1 edit

lambition

Member

My problem was solved when I changed my modem.
I still am not quiet sure it really was the modem that was damaged or its just something between D-Link DCM-202 (my old modem) and COX.

What I found out was that it was losing connection every 12 or 24 hours. (sometimes it stops working after 12 hours and some other times it stops working after 24 hours.)
I have concluded that the modem is failing to renew it's IP address (IP address of the modem it self) for some unknown reason.
When I contacted technical support while I lost connection, ref. could see the modem is on-line, however he wasn't able to pull off any information from it.

The last thing I could try was changing the modem. I got WebSTAR DPC2100 (one that COX is giving out these days) from my friend and changed my modem. It is working fine now.
visormiser
Premium Member
join:2004-02-10
Alexandria, VA

visormiser to lambition

Premium Member

to lambition
Having the same problem here in Annandale for the past week now. About once a day (sometimes twice), no Internet. All lights on on the modem (Motorola SB5120), but only thing I can access is the router's interface and the modem's interface.

A Cox rep told me this was a modem-router sync problem and that I needed to get another router. I'm not buying it -- a new router or his story. I've read too many of these threads about similar problems in N. Va. about unexplained outages that involve random disconnects with the router and modem.
lambition
join:2004-08-26
Oakton, VA

lambition

Member

From my experience, it almost never is the router problem.
Easiest way to test would be connecting directly to the modem without a router.

Replacing my modem to DPC2100 did fix my problems. No more resetting modem everyday
sqwish
join:2008-08-07
New York, NY

sqwish

Member

Hey guys. I have a DLink DCM-202 Cablemodem and I can say with a certainty that replacing the cablemodem FIXES the disconnects-every-12/24 hours thing. Sometimes it would disconnect randomly or on the 6 hour mark (after a DHCP lease) but it was usually 12/24 hours after the DHCP lease was acquired.

New cablemodem is the same kind COX uses: Motorola SB5101.
(I did not want to take any chances of it not working)

Now the real question becomes, what did COX change that broke my old DLink DCM-202? The disconnects started right around mid-June which is coincidentally when I cancelled my Limited-Basic TV service and was only subscribed to HighSpeedInternet.

Can I get any corroboration for this? I find it odd that my cablemodem would choose to die on its own around the same time as the other DCM-202 owner on this thread. I find it more likely that COX changed something on their side that prevents DCM-202s from working properly, or something they changed when they cancelled my LimitedBasic CableTV subscription did it.

Keep in touch guys, something isn't right here

Cheers,

Mark
lambition
join:2004-08-26
Oakton, VA

1 edit

lambition

Member

It must have something to do with COX upgrading NVA network to DOCSIS 3.0.

When you canceled your basic cable TV, COX technition should have installed a filter that filters analog signals. If you remove that filter, which is installed inside drop box in your backyard or telephone pole, then you will get all analog channels. (This is illegal though) That should not cause problem with cable modem unless the filter is bad.

Since COX never sold DCM-202, I don't think COX will do anything other than telling us the modem is bad.
jfoj
join:2005-05-06
Mclean, VA

jfoj to sqwish

Member

to sqwish
sqwish,

Suggest you look this thread over: »[VA] Intermittent Internet Issues???

I would bet if you put your DCM-202 back online it would work fine at this point.

About a week ago Cox made a repair/config change to their Fairfax network that resolved the modem hanging problem with many modems and the T3 timeout, intermittent Internet connection and unstable download speeds.

For the past week, I think anyone who was originally impacted by this issue has been happy.

If you have some ongoing problem(s) it may well be something else.

jfoj

CoxTech1
join:2002-04-25
Chesapeake, VA

CoxTech1 to lambition

Member

to lambition
To clarify regarding modem support, simply because the modem is not a model provided by us doesn't mean we will not support it. We don't have any tools to conclusively identify a modem as having failed. Usually this determination will be made by replacing the modem and observing the results.
sqwish
join:2008-08-07
New York, NY

sqwish to lambition

Member

to lambition
RE: Cancelling limited basic cable and getting a filter:

- Yes, when I cancelled limited basic cable, a COX tech came out and put on a "red filter" (6" long silver cylinder, about as thick as my finger, with a 1" red band on one end) From then on, my cablemodem signals were unusable, causing dropouts on average once an hour.

I wanted to take the filter off myself because I knew it was the cause, but I relented and called COX; they sent a tech who removed it himself. Turns out there is a bad manufacturing batch of these red-filters and I got one of them. The bad ones cut out more of the frequency spectrum than they're supposed to. Hmph.

Re: DOCSIS 3.0 upgrades possibly causing the DCM-202 issue: could be.

Re: COX fixing something last week in their system and maybe the DCM-202 would work now if I tried it again:

- I might just do that. I have no problem with my old modem. The question is, would it break again later if COX changes something *else*? If I were COX I'd test all my changes against Motorola Surfboard5101 modems before all others (if that's what I rented out to my customers)... so it's probably safer using that model in the short term before the DOCSIS 3.0 rollout.

I love the quick response on this forum! I should have joined sooner!

Cheers all