Network Switch LED’s

[wrems]

My switch lights either amber (10/100) or green (1000) and can vary the intensity of the color to show bad cabling I guess.

Is it a good/accurate measure/test to use the color scheme on the switch to test drops and patch cables? I’ve basically moved my laptop around to each node to test for GigE (green light) connections. In doing these tests I have come up with combinations of patch cables and keystones that needed to be examined and fixed, thus it helped me find some problems. Now, each node is known to light green when I hook my laptop to it and I’ve tossed any suspect patch cables.

Is this a good test to know if everything is good with the cables and such? I’ve been having intermittent issues with the internet and Comcast is telling me its on my end. Short of buying a tester, is testing this way proving that all is good on my end? I suspect my stuff is ok... But I want to rule out any patch cord/cabling problems.

[paulbeers]

I highly recommend a tester. Heck you can pick 'em up for less than $10 bucks on ebay. I once had a problem that was causing my router to shut down and couldn't figure out why. Turned out that a couple of my keystones were wired incorrectly (my fault of course). I had reversed a couple of pairs. Oops. Everything was telling me they were connecting correctly, but it wasn't until I tried to pass data thru them that I had problems.....

[Spectrum]

Originally Posted by wrems

My switch lights either amber (10/100) or green (1000) and can vary the intensity of the color to show bad cabling I guess.

Is it a good/accurate measure/test to use the color scheme on the switch to test drops and patch cables? I’ve basically moved my laptop around to each node to test for GigE (green light) connections. In doing these tests I have come up with combinations of patch cables and keystones that needed to be examined and fixed, thus it helped me find some problems. Now, each node is known to light green when I hook my laptop to it and I’ve tossed any suspect patch cables.

Is this a good test to know if everything is good with the cables and such? I’ve been having intermittent issues with the internet and Comcast is telling me its on my end. Short of buying a tester, is testing this way proving that all is good on my end? I suspect my stuff is ok... But I want to rule out any patch cord/cabling problems.

I've never seen a switch that varied intensity to show health of a link. Anything's possible, but I wouldn't rely on it as a definitive test. Only way to get one of those is a cable tester and that's kind of expensive for a one off test. The cheapest way to go would be to just replace a single link between you and the cable modem. Say replace the cable between one box and a switch and then the cable from the switch to the router and the cable from the router to the cable modem then use that link as your testbed. As long as you know are competent at making the patch cables (or buy them premade) the odds of replacing a bad link with another one is pretty low.

Comcast blaming your equipment is SOP. Many of the techs will absolutely refuse to admit that it is even remotely possible their equipment is at fault and try to steamroll you into doing the troubleshooting for them.

You didn't mention what kind of issues you are having, but if you are getting huge latency spikes or dropped signals and you can catch it in the act then ping your router and everything is fine but pings outside the network are dropped or have high latency, odds are the problem is between the router and the rest of the world. In that case it could be the cable modem or anything further down the line, but that's Comcasts responsibility

Paul and I have different opinions on quality test gear it seems. I've never been fond of the plastic fantastics

[paulbeers]

Originally Posted by Spectrum

I
Paul and I have different opinions on quality test gear it seems. I've never been fond of the plastic fantastics

Actually, I usually use my Fluke CableIQ Residential Qualifier, but your average person has no reason to spend 1K on an ethernet/cable/tester. The cheapos won't guarantee that you will get gb speeds, but at least they will make sure you wired it correctly!

[Spectrum]

Originally Posted by paulbeers

Actually, I usually use my Fluke CableIQ Residential Qualifier, but your average person has no reason to spend 1K on an ethernet/cable/tester. The cheapos won't guarantee that you will get gb speeds, but at least they will make sure you wired it correctly!

True, and it does beat trying to do a continuity check with an Ohm meter

Although the tester that came to my mind was a $60-$80 Paladin, not a 1k Fluke. I had a Fluke DMM that I absolutely loved until it got stolen in a break in; they make quality stuff.

[wrems]

So here’s the background, it’s lengthy but I think detailed enough to get a good grasp of my situation...

Lately my internet has been very flaky. I have Comcast. So far my troubleshooting has lead me to change out all coax with properly terminated quad shield RG6. I’ve replaced the coax splitters, I’ve replaced the cable modem with a new one and I’ve replaced the patch cords. Still I have problems. I have had techs out here and they insist its the rest of my network, since I have a lot going on here, not really but they think so... All they do is check some of the levels and they say they’re all fine. Of course it’s always working fine when they’re here...

Here’s my basic setup. I have the main coax line coming into the house from the street, where it gets split by a 2-way splitter, one leg to the modem and the other to another splitter to distribute around the house etc. I have a router and a switch next to the modem (which are in the basement). I have a wireless access point upstairs for my laptops. My internal network is great and I’ve tried to explain to the techs that my network works fine regardless of my internet working at all, therefore, my internal LAN is fine. Plus, when I have the internet problems I check the modem and the led for Cable is off, it should be solid green. This tells me that it’s the modem, splitter, or the line entering the house. I changed all of this as far as I can go, to the grounding block outside my house. Maybe I need to change the grounding block too?

Now here’s another consideration to add. This morning my internet goes out. I do the usual power cycling/resetting the modem etc. No go. I connect the modem directly to my server bypassing router and switch. No go. These tests are while the 2-way splitter is still in place. I call Comcast to make sure there is no area wide service outage, they confirm there is no outage. I replace the splitter with a DC tap. Bingo I’m back online.

As happy as I am to get this to work with the DC tap, I’m ambivalent since it has been working fine with the 2-way splitter for a long time. The tech also said that regardless of the 2-way splitter my levels are fine and that the presence of a splitter wouldn’t cause enough degradation to be a problem. Ok, so while I’m typing this part... My connection drops again... That’s with the tap. I reset the modem and nothing. Remove the tap and go straight into the modem with the coax bypassing all splitters and bingo its working again.

I’m at a loss here. Does anyone have any ideas? Could my hardware even remotely be causing any of these issues? Comcast insists that its on my end. What else can I check, test or do to determine what is going on here?

I’m beginning to think it’s a moisture related issue with their connections etc on the pole. Or, maybe the grounding block, my visual inspection doesn’t indicate anything out of the ordinary with the block... I’ve asked Comcast repeatedly to go up the pole and check out the connections and they will not comply for whatever reason. I’ve noticed that most if not all of these issues happen in the morning while it’s a bit cooler. Then by afternoon and into the evening everything presumably dries out in the heat of the sun and my internet problems are almost non existent, the afternoon is usually when they’re here. It’s inconsistent, I don’t have these problems every morning... At the same time, I don’t have any of these issues in the evening.

What do you guys think?

[gplasky]

It will be time consuming but I would start with the basics. Use various PCs for a period of time being just plugged into the cable modem. Internet benchmarks, etc to see if you can break it. Once satisfied with that put your router back into the equation with a few PCs plugged into the router. (I would leave out the splitter during all of this.) Your router may be going or may be misconfigured. If you see issues reset your router back to the default settings and just do a basic reconfigure. (no wireless) until you are satisfied.

As an example of the router causing modem issues I installed a new router last weekend. I almost followed the instructions to the letter. But I thought pluggin/unplugging the modem would suffice. After the router configuration the cable modem would go thru its power up and light display and then the lights (all but the power) would go out and no access to the Interent. It was not until I actually pressed the reset button on top of the modem before it worked correctly.

Also my setup consists of 1 cable into the house. One 8-way distribution amp for all of the cable connections. Initially I had a 2-way splitter with one to the amp and one to the cable modem. Even though that was recommeded I switched it and found it wasn't necessary.

Gerry

[wrems]

Are you saying the router can knock the cable modem offline? I've got 2 other routers that I can test with.

[Spectrum]

Originally Posted by wrems

Are you saying the router can knock the cable modem offline? I've got 2 other routers that I can test with.

I've seen some strange stuff, but I've never seen a router take down a cable interface on a modem; if anything I would expect it to give the Ethernet interface on the modem grief. Not to say it's not possible, just highly unlikely.

The fact that the cable light is off when you are having problems speaks volumes. If your modem is a DOCSIS 3.0 modem (may work with DOCSIS 2.0 too) you can probably get to it's status/configuration page by pointing a browser to http://192.168.100.1 That seems to be pretty standard now. If you can get to that you may be able to see something in its logs or you can watch it and see what happens during an outage. I know the Arris modems that Comcast rolled out here recently give you the status page strait up but the Ubee's had it behind a login/password which had never been changed for mine it was user/user

Try getting to the modem status and see what you come up with.

[gplasky]

Originally Posted by Spectrum

I've seen some strange stuff, but I've never seen a router take down a cable interface on a modem; if anything I would expect it to give the Ethernet interface on the modem grief. Not to say it's not possible, just highly unlikely.

I thought the same thing. But until I actually reset the cable modem the green transmit, receive, online light would come on for about a minute and then all turn off. I immediately could not get to the Internet. I was calling the cable company thinking they might need to do something. Everything but the actual power light would just turn off. As soon as I hit the reset button all the lights came on and I could get on the Internet. very strange.

Gerry

[stanger89]

Originally Posted by Spectrum

Although the tester that came to my mind was a $60-$80 Paladin, not a 1k Fluke. I had a Fluke DMM that I absolutely loved until it got stolen in a break in; they make quality stuff.

FWIW, even the "expensive" cable testers don't "qualify" cable, they only do continuity tests. What you get with the more expensive ones is better display of how the wiring is wrong.

Basically if the tester is under $1k, it's not going to "qualify" the cable, ie test that it can actually do Gig-E.

[KeithAbbott]

Originally Posted by Spectrum

If your modem is a DOCSIS 3.0 modem (may work with DOCSIS 2.0 too) you can probably get to it's status/configuration page by pointing a browser to http://192.168.10.1

I think you may have meant http://192.168.100.1

[MattHelm]

Originally Posted by wrems

... I replace the splitter with a DC tap. Bingo I’m back online.

As happy as I am to get this to work with the DC tap, I’m ambivalent since it has been working fine with the 2-way splitter for a long time. The tech also said that regardless of the 2-way splitter my levels are fine and that the presence of a splitter wouldn’t cause enough degradation to be a problem. Ok, so while I’m typing this part... My connection drops again... That’s with the tap. I reset the modem and nothing. Remove the tap and go straight into the modem with the coax bypassing all splitters and bingo its working again.
...

Despite what they are telling you, I think you have 2 problems:
1. slightly low signal strength. (built in Automatic Gain Control can hide this sometimes)
2. A bad splitter. (Please note, a PERFECT splitter still looses 1/2 (-3db in RF talk) the signal.

I would suggest a good cable amp with 0 DB return lose like the below:
http://cabletvamps.com/Products/EDA-FT08300.htm
(that one sounds like overkill for you, but has a GREAT feature list. (I own 2 of the older models, and they are GREAT amps)

Of course, you might only need a good splitter, so you may try that first, being cheaper, and easier to find.

Oh, grounding blocks can sometimes go bad. If it is replaceable, and you are ordering anything else anyway, I'd just get a new one.

Also, if you really think water is getting in, there is some goo you can buy:
http://www.mjsales.net/items.asp?Fam...D=34&Cat3ID=27
that you put IN the ends when making connections. This should only be needed on always in the weather connection, or on the ground.

[Spectrum]

Originally Posted by stanger89

FWIW, even the "expensive" cable testers don't "qualify" cable, they only do continuity tests. What you get with the more expensive ones is better display of how the wiring is wrong.

Basically if the tester is under $1k, it's not going to "qualify" the cable, ie test that it can actually do Gig-E.

Yep I was thinking continuity only. There is absolutely no need to have a tester capable of qualifying the line unless it's being used for business purposes. Or if you just have tons of cash layin around

Originally Posted by KeithAbbott

I think you may have meant http://192.168.100.1

Typo got me and I didn't actually click the link to verify it Thanks for the catch! I fixed it in the original post to prevent any future confusion.

[wrems]

Originally Posted by gplasky

Internet benchmarks, etc to see if you can break it.
Gerry

Any particular ones? I'll try breaking it in the morning. I can do anything to it all night long without a hitch. We'll see tomorrow morning.

I did some testing on my own through the modem itself. Not sure precisely how accurate these figures are but they all seem quite good.

No Splitter - Straight from the street into Cable Modem
Downstream S/N: 37 dB
Downstream Power Level: 6 dBmV
Upstream Power Level: 46 dBmV

DC Tap
Downstream S/N: 37 dB
Downstream Power Level: 3 dBmV
Upstream Power Level: 50 dBmV

2-way splitter
Downstream S/N: 36 dB
Downstream Power Level: 2 dBmV
Upstream Power Level: 51 dBmV

Each of these tests are well within the margin of a good quality signal. I think I'll catch it in the act in the morning and pull these levels again. I still believe that it's somewhere streetside... At the same time, I'm going to get a new WAP and router just to be safe. Can't hurt right?

For now I'm sticking with the DC tap since it is basically the same levels as going direct to modem.

[wrems]

Also, any specific recommendations for continuity testers so I can test my patch cables and drops?

[wrems]

Update...

Gplasky, I think you were right.

I went out and picked up a new router http://www.newegg.com/Product/Produc...82E16833162134 and also a continuity tester http://www.paladin-tools.com/view_to...&parent_id=376 . I tested all drops and patch cables and all are shown to be working well. I’ve changed my setup and removed my GigE switch and have just the absolute necessary hard wired connections routing through the Buffalo router. Not only am I getting better wireless performance I’ve been beating this thing up and its been a champ. My old Linksys DDWRT I think is ready to be retired.

I’ve got an AP coming monday too http://www.newegg.com/Product/Produc...-268-_-Product . I think my new setup will prove to be much better than my old one.

I’m still watching my broadband like a hawk but it seems to be performing really well with the new router. I think it may have been the router all along and it was the last thing I was paying attention to. I didn’t think it could take down my cable modem... I think it was.

I’m still running the stock firmware on the Buffalo router and after a while of known good use I’ll be putting either Tomato or DDWRT. I’ve run DDWRT in the past and like it, but I’m thinking of giving Tomato a go. Anyone using Tomato, or have any reasons why I should stick with DDWRT?

Thanks again for all your help!

[Spectrum]

So how's it behaving after a few days? I assuming well, but I'm surprised that it was the router by the description of the problem. It's no surprise that a router can cause connection problems, mine seem to flake out about every 18-24 months, but I still fail to see how a router can cause the cable modem to have errors on the cable interface. Very bizarre!

[wrems]

My new setup has been working great for a few days now, better than it has for sure. I did catch it dropping connection to the internet for the first time yesterday; again... In the afternoon too, up till now its been pretty consistently inconsistent in the mornings. It dropped the connection and then came back online on it's own several minutes later...

I checked the levels of the modem and they increased on both downstream and upstream power levels, 5 and 55 respectively. The levels went back to normal (3 and 50) just a few minutes later... I’m not sure what that means. I’m pretty sure it’s got to be on Comcast’s side of things now that I’ve basically changed out everything and tested everything else.

On a side note, the continuity tester I got seems to do ok. I noticed when I made a new drop for my AP, the tester said the line was fine. So I connect my laptop to that drop and check the switch for green GigE connectivity. No green. I knew it had to be with the keystone so I re-did it and got the same result, no green led on the switch. I finally put an rj45 plug on it and went direct and then I get green. So what is the switch detecting or sensitive to for it’s status? The documentation just said it detects link, speed and activity. It’s a nothing special unmanaged switch Netgear gs108. I was using one of those tool-less keystones which I didn’t like over the regular style, it never seemed to make as solid of contact... Needless to say but I wouldn’t buy them again.

[wrems]

Good news, Comcast was out here again today. Internet dropped at least 3 times today. They are going to be running a new drop from the pole to my house. I've been asking them to get up that pole for some time and check things out. They never do. At my last place I had similar problems and it wasn't until a tech actually got up there that he found a completely corroded connector. He put a new one on and all my problems went away.

This guy said he thinks it may be moisture related. Especially since it has rained on and off for the past couple of days. He thinks it's possible that squirrels may have chewed up something and that moisture is getting in somewhere as a result...

Regardless, I'm happy they'll be running a new line altogether. He said he would check out and see if one of our neighbors drops may be leaking interference into my line while they're changing it out. Best part is they said they could get it done today!