# Gigabit switch loses 1gbps connection



## Carsomyr (May 30, 2019)

_I have a 1gbps internet connection from my provider. I have an ethernet cable (cat 6a) going from my providers router/modem to my gigabit switch downstairs... 

The cat 6 cable that feeds the switch with internet should be constantly showing two led lights... Which means 1gbps signal... 

Instead, it STARTS with 2 lights, and after a few minutes to a few hours the inevitable always happens... I lose on of the 2 lights and my speeds drop to 100 Mbps or less... 

II don't understand why this happens... I tried rebooting every device including the switch and the modem, I tried new cat 6 cables and the problem persists... 

Whenever the problem appears, I'm forced to unplug the ethernet cable that feeds the switch to provoke the 1gbps signal into coming back... It sometimes requires many tries.... When I do get the 2 lights back I always end up losing one to the lights and the speed drops. 

PLease help me fix this problem! 

P. S. II'm thinking maybe the switch or the modem is defective. I'll have the hub/modem replaced tomorrow to see if it fixes the issue _


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## Solaris17 (May 30, 2019)

replace the cable?

Edit: whoops didn’t see you replaced the cables


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## FordGT90Concept (May 30, 2019)

The reason why the rate falls is because the SNR gets too low to sustain the higher bitrate.  You tried multiple cables...when you did that, did you run them via separate paths?  An unshielded CAT6 cable parallel to a power line will likely have SNR issues.  If the second cable took a completely different route then the cable likely isn't to blame.  What's the distance of the cable run?

Have you tried a different port on the switch and router?


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## Carsomyr (May 31, 2019)

FordGT90Concept said:


> The reason why the rate falls is because the SNR gets too low to sustain the higher bitrate.  You tried multiple cables...when you did that, did you run them via separate paths?  An unshielded CAT6 cable parallel to a power line will likely have SNR issues.  If the second cable took a completely different route then the cable likely isn't to blame.  What's the distance of the cable run?
> 
> Have you tried a different port on the switch and router?



Thanks for the reply. 

Here's exactly how I'm setup:

There's a cat6a cable that runs from the 2 in 1 modem/router to my switch downstairs. That cable is probably about 30-40 feet tops. Probably a bit less. It doesn't run along other cables. It's by itself. 

My netgear gigabit switch has a total of 4 devices connected to it. An Xbox one x, and htpc, a home theater receiver and the fourth is a cable that goes from the switch to an in-wall ethernet connection which feeds my UBIQUITI AP upstairs... 

I haven't really tried putting the incoming cat7 cable that carries the internet to the netgear IN another port. I'll try that. 

What did mean by "SNR"? 

I'm pretty sure the cat 6a cable is shielded. Its a rather standard looking cat6a cable. It's true that sa portion of it runs alongside other cables when it arrives in my home theater room. The other cables are ethernet ones as, an Hdmi, and 1 set of speaker cables. 

Please do give some more details, I really want this problem fixed. Because I pay for gigabit internet but I'm trapped in the constant 100mbps problem due the switch or other component acting up


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## FordGT90Concept (May 31, 2019)

That home theater receiver might be 10/100 and that switch might be downgrading all traffic to 10/100 because of it (lower end switches like to do that).  Which model of switch is it?  You can test this theory by leaving just the Xbox One X (definitely 10/100/1000) and the cable to router plugged in.  If it doesn't degrade the performance, that's probably the problem.

SNR = Signal to Noise Ratio

Shielded CAT6 cables are much thicker than non-shielded CAT6 cables and much stiffer.  CAT6A is much thicker than CAT6 because each pair is individually shielded inside of the cable.

Speaker cables are never shielded if they're post-amp...they can wreck havoc data cables.

Wait, is the entire router dropping to 10/100 or just the cable to the switch?  I was under the impression it was just the latter.


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## Carsomyr (May 31, 2019)

Solaris17 said:


> replace the cable?
> 
> Edit: whoops didn’t see you replaced the cables



In truth I only replaced the small ethernet cable that connects to the long one that comes from my router. See the linked youtube video to see what my setup looks like it might give you some insight as to where my problem comes from.



FordGT90Concept said:


> That home theater receiver might be 10/100 and that switch might be downgrading all traffic to 10/100 because of it (lower end switches like to do that).  Which model of switch is it?  You can test this theory by leaving just the Xbox One X (definitely 10/100/1000) and the cable to router plugged in.  If it doesn't degrade the performance, that's probably the problem.
> 
> SNR = Signal to Noise Ratio
> 
> ...



I'm not what you mean by post amp. My speakers aren't pre amplified if that somehow relates to what you are talking about.

I have a verying fiber optics cable. I'll try and bring the modem downstairs and connect it directly to the switch and see if the problem persists... If it does you guys were probably right about the interference. I'll do that right now. The switch mode is the netgear prosafe gs108 gigabit switch.


Here's a video of my setup. I know it's a mess, be indulgent if you can


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## FordGT90Concept (May 31, 2019)

GS108 is a good switch and is capable of running mixed mode 10/100 and 10/100/1000.  It could be defective...but I think I see your main problem:  That black cable is your 30-40 foot run?  That doesn't look like CAT6.  In fact, it looks so small, it might be CAT3 (aka phone wire).  Those beige looking cables, those are legit CAT5 or CAT6. 





Brown: Look at how all the wires inside fan out to cover the width of the connector.  This is the way it should be.
Red: Look how it's tiny and goes straight through.  I suspect it is only using 2 pins or 4 pins.  CAT5/6 needs 8 pins--the width of the connector.
Violet: Look how thin this cable is compared to...
Blue: This is a legit CAT5 or CAT6 cable. It has 4 pairs of solid core wires in it.
Yellow: You got another nasty cable/connector over here too.  If it is not causing problems now, it likely will in the future.

If it were me, I'd cut that connector off and see if it is actually legit networking cable:




This is what legit CAT6A looks like inside (very thick, stiff cable):





There's absolutely no way CAT3 can do gigabit.  Well, maybe it can over a few inches but not over feet.  It likely tries to do gigabit over it, that fails, so it is falling back to 100 megabit as it should.  Technically, CAT3 shouldn't be used for more than 10 megabit.


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## Solaris17 (May 31, 2019)

I agree whatever that black cable is needs to go. If thats the uplink cable thats the first thing id throw away.


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## Kursah (May 31, 2019)

There's CAT6 ultra slim to keep in mind.









						Cat6 Ultra Slim Stranded CM - 28AWG, UTP, Bulk Networking Cable
					

Shop Infinity Cable Products for Cat6 ultra slim CM stranded cable. This cable is 28AWG, 1000ft, stranded conductors, unshielded, UTP and UL Listed.




					infinity-cable-products.com
				






			Fiberdyne Labs, Inc. Ultra Slim Mini-6 Category 6 Patch Cables
		






I use it all the time, but only for patch cords and short runs. I haven't had any issues using it the past couple years, but could see a longer run easily getting damaged and I have to imagine the thinner strands have to lose signal faster than standard spec. Much of what I found says 55 meters or 180 feet.

@Carsomyr have you bypassed your switch and connected directly to your PC or laptop to see if the same issue occurs on that cable?


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## FordGT90Concept (May 31, 2019)

But look how slim still uses all 8 pins.  It looks like his cables don't.

Even so, no way should slim be used for 30+ feet runs.

I use CAT6 FTP for 1' runs.  Maintains shield grounding that way.


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## Solaris17 (May 31, 2019)

I also know they make flat cable, my big thing with slim runs is the heads are all the same, I would be afraid that the jacket has been tugged out or a wire is ripped or snapped either in the tip of near the jacket stress point.


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## FordGT90Concept (May 31, 2019)

I have a very hard time believing a flat cable can meet CAT6 specification.  CAT5, sure, but CAT6 requires a divider between the pairs to prevent crosstalk.

Anyway, my concern is that you can see through the connector where there should be cables.  I think he's got CAT3 cable with RJ45 4-pin connectors.  You can see the router/switch attempting to connect at gigabit three times before it gives up and downgrades to 100 megabit.


Wait a minute, it looks like a short patch cable?  And it works fine with a normal network cable and not with the slim patch cable?  If yes, there's your proof that slim patch cable is garbage.


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## Solaris17 (May 31, 2019)

FordGT90Concept said:


> I have a very hard time believing a flat cable can meet CAT6 specification. CAT5, sure, but CAT6 requires a divider between the pairs to prevent crosstalk.



I didnt mention CAT6


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## newtekie1 (May 31, 2019)

The thin cable is very obviously only being used for the short run between the cable coming from the router and the switch.  The long cable running between the router and the switch is a thick normal cat6 cable, and should have no problems with 1Gb/s.

Also, he said he hasn't tried replacing the long cable between the router and the switch, and I'd bet that is where the problem is.

First thing I would do is run a new long cable between the router and switch, don't use those RJ45 female jacks on the ends, just put regular RJ45 ends on it(or better yet just use a pre-made cable) and plug the cable directly into the router and switch.  Then see what happens.  You don't even have to route it fancy like the current cable it, just get it plugged in and see if the problem continues.


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## Carsomyr (May 31, 2019)

Ok guys. Heres an update. I did the following:

The modem router in the video which had the long cat6a cable running downstairs... I decided to bring it downstairs. I instead replaced the long cable with a long fiber optics cable... Which in the end brought my modem router right next to the switch... 

For a while I thought that fixed the issue until this morning again, the switch goes from 2 lights to 1 light again. 

This time around I thought of something else to try. I ran a small ethernet cable from the modem router to the switch as usual, but this time changed the lan port on the modem router. I plugged it in the modem router lan port number 2 instead of number 1.

Ever since, the connexion has been very good. 1gbps, two lights... 

I'll have to see if it lasts... 

Yesterday I decided to re stick my cable mat which you see in the video to the floor. It's the thing that hides my hole theater and network cables... I used my heat gun a little to make it stick better... I believe I damaged the high quality super thick 25 ft Hdmi cable that was under it because of the heat lol

The xbox signal doesn't reach my home theater tv anymore lol... 

Apparently this is trouble shooting and problem solving week for me lol


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## FordGT90Concept (May 31, 2019)

newtekie1 said:


> Also, he said he hasn't tried replacing the long cable between the router and the switch, and I'd bet that is where the problem is.


Yeah...cable tester would be super userful here...


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