Is this termination no bueno? 2.5G network drops

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Digital Viper-X-

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I have been fighting some disconnects on my PC and switch in general.

Topology is something like this...
Archer Router with 2.5G ports -> Cat 6 home wiring (builder installed cat6 genesis 6360) -> Office keystone/jack -> standard cat6 UTP cable -> 2.5G Zyxel MG-105 5 port switch (Def overheats) -> cat 6 flat cable (20f) -> PC with a Realtek 2.5gb (Asus TUF X870)

The symptoms are that sometimes my PC drops the connection and reconnects at 100/100, but the Synology NAS keeps it's 2.5G connection on the same switch. Another is that on the router I can see the entire port loses connection (Zyxel super hot at this point and it seems it is common, it is getting replaced under warranty) and all devices on that switch lose connection.

So far I have identified the most likely culprits being switch as 1 problem, and the cable going to the PC as another. I have moved everything to my gigabit Asus router in AP mode for now and only my PC has been dropping, so we can confirm either the switch, or wire to the switch (unshielded) being bad.

Zyxel sent out a replacement that I should get tomorrow. It gets hot enough to be uncomfortable in your hand even standing up and getting maximum air exposure without having a dedicated fan on it.

I ordered some Cat 6A U/FTP cables from Monoprice to replace both the Jack -> Switch and Switch -> PC which should eliminate that as being an issue. Hopefully that solves it. Current cables are thin UTP cables. I have tried setting the PC connection to 1GB manually as well, and still it will drop to 100 at times, even on the Asus router.

One last issue that It could be is the termination on the keystone/jack, how does this look? It could be better with less exposed wiring before it enters but I have never had it setup like this before to know any better.

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id suspect the flat cable before that bit of extra exposure.
 
Digital Viper-X- said:
Just lift the cap off and pinch back down when cables reseated?
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yup. pop it off and if it has tabs that go down into the groove its one of those. then you can just shuffle the wires in to where youre happy with it, push the cap back on and trim the extra. if not, id just leave it.
 
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Dropping all the way to 100 suggests a bad line. Gigabit+ needs all 4 pairs. 100 needs 3. That's just a guess, but I'd start by redoing the keystone jacks and swapping patch cables. Patch cables first. They're cheap and having spares is a good thing. If that doesn't work I'd redo the wiring in the keystone jacks.
 
Also you want all the individual wires to be the same length going into a keystone jack. It's unshielded Cat6 so cutting off the plastic wrapper early doesn't really matter. You just want them the same length and you want to un-twist them as little as possible. When I put in a Cat6 or 6a jack I run the jacket into the jack, cut the wires even, and try to line of the ends of the wires with the outside of the jack so I don't have to cut off any wire.
 
zandor said:
Dropping all the way to 100 suggests a bad line. Gigabit+ needs all 4 pairs. 100 needs 3.
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100 only needs two pair. But downgrading on bad cable is definitely not in the ethernet spec, so who knows what rules are being followed. Negotiation happens at 1mbps, over the main two pairs, so it's really easy to negotiate to a connection that doesn't work.

If you're on windows, realtek's web page should have diagnostic tools which might tell you a bit about your cabling and help you figure things out, maybe.
 
toast0 said:
100 only needs two pair. But downgrading on bad cable is definitely not in the ethernet spec, so who knows what rules are being followed. Negotiation happens at 1mbps, over the main two pairs, so it's really easy to negotiate to a connection that doesn't work.

If you're on windows, realtek's web page should have diagnostic tools which might tell you a bit about your cabling and help you figure things out, maybe.
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No you're right, it's just 2. I looked it up. Thought it was 3. Not that I've really paid much attention to 100Mb in the last 15-20 years.

Bad connector can drop your speed to 100. Been there, done that. Picked up a spool of Cat6A, ran a line, oops ends didn't show up on time so I tried using a regular Cat5/5e/6 RJ45 plug. Ran at 100. Rock solid 100 too. It was probably possible to get it crimped properly on 6A, but not all that easy. The wires are thicker. Cramming all of them into a plug meant for thinner wires doesn't work all that well. At any rate I got the right plug, re-terminated the cable, and it was fine after that.

Just because the spec says negotiate over 2 pairs at 1mb doesn't mean your gear isn't checking the rest of the wires and automatically downgrading to deal with wiring faults.
 
zandor said:
Just because the spec says negotiate over 2 pairs at 1mb doesn't mean your gear isn't checking the rest of the wires and automatically downgrading to deal with wiring faults.
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Mostly means there's no published rules about how downgrading works though. According to spec, you should continue to negotiate to best mutually supported, even though it doesn't work...
 
Right now, we are humming along at 1gbps again... but it was at 100 for bit of the weekend. It seems to be happy with the cable now, when it drops back to 100 I will check again. The new Monoprice U/FTP cables arrived, so I will switch those out today along with the switch!
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For diagnosing something like this iperf is your friend. My parents house from 1995 has over 50 cat runs, and the idiot terminating the upstairs pretty much stripped off 3" and untwisted that much so all those iperfed at 100Mbs versus the 700-900Mbs that the downstairs and attic get. :mad::mad: I have so much re-terminating to do up there, and there's no service loops either, so I'll probably have to keystone it in the box and then run a cable to the plate with a coupler as a workaround. :banghead:

What crazy is that here we are over 30 years later and electricians are still doing this same crap today for 'ethernet installs'. :mad::mad:

I would iperf the cable in the walls, the patch cables you're using, the switch--basically each component individually. I have also seen marginal patch cables go from 1Gb to 100Mb over time as they fail, but it's basically just the connections failing over time.
 
toast0 said:
Mostly means there's no published rules about how downgrading works though. According to spec, you should continue to negotiate to best mutually supported, even though it doesn't work...
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In my case this was an old NetGear switch from maybe 2003 or so (20+yo & still works!) and an integrated Intel NIC on an X79 board from 2012. If Intel and/or NetGear are doing it I bet it's common. Auto downgrade is also more user friendly, so I can certainly see why they'd try to detect wiring faults and run at a lower speed if possible even if it's not in the spec. It would have made even more sense back when that switch was built and there was a lot of Cat5 cable around. Back when I got that switch I had to use cards for 1Gb. Mainboards didn't generally have 1Gb yet.

Now that I think about it a bit more, I bet that old Netgear switch is doing it. Back when I got it I still had a bunch of Cat5 patch cables. Plug one of those in and it'd run at 100Mb.
 
SamirD said:
For diagnosing something like this iperf is your friend. My parents house from 1995 has over 50 cat runs, and the idiot terminating the upstairs pretty much stripped off 3" and untwisted that much so all those iperfed at 100Mbs versus the 700-900Mbs that the downstairs and attic get. :mad::mad: I have so much re-terminating to do up there, and there's no service loops either, so I'll probably have to keystone it in the box and then run a cable to the plate with a coupler as a workaround. :banghead:

What crazy is that here we are over 30 years later and electricians are still doing this same crap today for 'ethernet installs'. :mad::mad:

I would iperf the cable in the walls, the patch cables you're using, the switch--basically each component individually. I have also seen marginal patch cables go from 1Gb to 100Mb over time as they fail, but it's basically just the connections failing over time.
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When it is connected at 2.5GB, it gets well over 1gbps when I am pulling files off of my NAS(also on 2.5GB) , would it impact the network speed? I have used IPERF from my nas to pc before for testing and it did show that the 2.5 was working.
 
Digital Viper-X- said:
When it is connected at 2.5GB, it gets well over 1gbps when I am pulling files off of my NAS(also on 2.5GB) , would it impact the network speed? I have used IPERF from my nas to pc before for testing and it did show that the 2.5 was working.
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Bad cables can reduce speed. Your NICs could very well negotiate 2.5Gb, run at that speed, and oops occasionally have a glitch causing packet loss and a retransmit and run slower overall. The more packets get dropped the lower the throughput.
 
Alright, so after about 2 weeks with the new switch and new cables, everything is rock solid, until the new switch degrades enough from the high heat :).

Will replace it eventually with a POE switch when I make some runs for outdoor cameras. But for now it is doing the jerb. everything is running at 2.5 or 1gbps (by design) so I can safely say, it was switch and or cables. Looks like the termination is not causing any issues.
 
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