Weird cabling issue (Solved)

[ColinTaylor]

No need, I can see issues running iPerf3, I peak out at sub 900Mbps client to server (server upstairs) and doing a reverse test I end up with peak speeds of 300Mbps, so something is going on here.

How are you performing the reverse test? iperf can give inaccurate results sometimes when using iperf's built-in "reverse" option. Instead just swap around the devices running the client and server. Also, don't run iperf on the router itself, use two PCs connected to the same switch.

 

[Samir]

Normally I would've, but the installation was really ugly with three cables sticking out of the wall in the living room, something I didn't want to have after having made the rest of the place look really nice and tidy.

I completely understand. And that's why they made keystone couplers like this to make it neat and painless:

Going to have to get some new sockets and some tools... Worst case I'm going to have to try and run a new cable

I used a cheap punch down tool, but with a metal part for the punching.

I'm almost 100% sure you don't need to run a new cable as it did work previously. I'd try punching down the keystone again first, and if that doesn't work, just put another rj45 on it and use a keystone coupler to 'tidy it up'.

 

[TheLostSwede]

Re-did the termination and now my router only syncs at 100Mbps...
Ok, fine, this is clearly either the cable or the jack or my shoddy work, but...
I still don't get the same upload speed as I had before, when doing a quick test using Speedtest. I'm still at least 5Mbps slower than I should be, but the download has no issues, as it's hitting 95Mbps, which I guess is kind of what you can expect from a 100Mbps Ethernet connection. I really can't figure out why the upload won't go back to full speed...

I've also moved the router downstairs and it has no issue doing the old speeds connected with a 1m patch cable to the cable modem.

Edit: Snipping the end off the end bits in the keystone jack got the sync speed to go up to 1000Mbps again, but not the actual network speed...

Edit2: Ok, back to the not quite there speeds again after rebooting the cable modem which seemingly synced at the wrong speed, hence getting 100Mbps download speed, rather than 200Mbps...
That said, still not getting the correct speeds upstairs, so I'm going to have to go and buy some more bits and try to change things around a bit...

 

[Smokindog]

You've got one or more wires not making a good connection if you're only getting 100Mbs. Common issue. THIS is why you need a tester

It's more than likely a Blue (4/5) or Brown (7/8) pair wire(s).

Re-did the termination and now my router only syncs at 100Mbps...
Ok, fine, this is clearly either the cable or the jack or my shoddy work, but...
I still don't get the same upload speed as I had before, when doing a quick test using Speedtest. I'm still 5Mbps slower than I should be, but the download has no issues, as it's hitting 95Mbps, which I guess is kind of what you can expect from a 100Mbps Ethernet connection. I really can't figure out why the upload won't go back to full speed...

I've also moved the router downstairs and it has no issue doing the old speeds connected with a 1m patch cable to the cable modem.

 

[ColinTaylor]

Maybe we need to see the bigger picture of how your network is laid out. i.e. what devices you have and how they are all connected to each other.

Also state the make and model of your router as well as your theoretical internet speeds (rather than xMbps faster/slower).

 

[TheLostSwede]

Well, it's not a hardware issue, that's for sure, but for your view pleasure, I have the following setup:

[1st floor] Cable Modem -> Netgear R7800 -> troublesome cable -> [2nd floor] TP-Link Archer C7 (set up as a Wi-Fi AP) -> Netgear GS110EMX -> 10Gbps to PC and NAS.

The connection between the cable modem and the R7800 is fine, as I get full speed there and I even get full speed on Wi-Fi devices on the first floor. Full speed being 200Mbps down, 30Mbps up, +/-5%.
I used to get the same speed on the second floor before changing the RJ45 connector to the jack.
Now I get ~175Mbps download tops and ~21-23Mbps upload.
The cable has not changed position, but for a small part, it's now next to another Ethernet cable which wasn't there before. Could this cause sufficient interference? It's the only thing I can think of that has changed beyond the jack.

 

[ColinTaylor]

OK thanks for the info. So just to be clear, when you do the speed test from the 2nd floor you are plugging your PC directly into the RJ45 socket and there are no other devices (wired or wireless) connected anywhere on your LAN (other than the router). And this is the same PC that you used to do the test when connected directly into the router on the 1st floor.

Interference? Possible but not likely. Also possible it's an intermittent wiring connection, i.e. it works OK for some of time but not others (e.g. when you move/touch the wiring). But that wouldn't normally manifest itself as a speed reduction. In either case I'd also expect to see very obvious Ethernet frame errors but your post #3 didn't show any. (Maybe try starting a long running download and gently wiggling the cable throughout. Then check the ethernet statistics again)

How long is the cable between the 1st and 2nd floors?

 

[degrub]

i wonder if the cable is CAT 5 instead of 5e ?
Can you read the marking on the jacket anywhere ?

 

[TheLostSwede]

i wonder if the cable is CAT 5 instead of 5e ?
Can you read the marking on the jacket anywhere ?

That's the problem, it's a black cable with no markings...

 

[degrub]

the black ones may have an impression rather than a print on the jacket.
How easy would it be to fish a new CAT 5e cable in the wall ?

 

[TheLostSwede]

the black ones may have an impression rather than a print on the jacket.
How easy would it be to fish a new CAT 5e cable in the wall ?

I'm aware of that, but I can't even find that...
Not that easy, I mean, there's supposedly tubing in the walls, but I don't have any blueprints and most of the ones I've tried to use before, ends up nowhere I can figure out. That said, there's already a cable going in this tube (since it's the one I'm using) so it should be possible...

 

[ColinTaylor]

@TheLostSwede Any comments on my post #27

 

[TheLostSwede]

As in yes, not much to wiggle, as most of it is inside a concrete wall and I have no idea, as it's inside a concrete wall.

Still no issues as far as I can see...

Interface Statistics

                           Received            Sent

Bytes                     476270880      1790355612
Unicast packets            15785158         6244502
Non-unicast packets         2063064          240384
Discards                          0               0
Errors                            0               0
Unknown protocols                 0

 

[ColinTaylor]

It might be worth checking for IP errors as well. There's usually a few, but there shouldn't be lots.

C:\Users\Colin>netstat -sn -p IP

IPv4 Statistics

  Packets Received                   = 583159
  Received Header Errors             = 0
  Received Address Errors            = 14
  Datagrams Forwarded                = 0
  Unknown Protocols Received         = 0
  Received Packets Discarded         = 1002
  Received Packets Delivered         = 583379
  Output Requests                    = 288669
  Routing Discards                   = 0
  Discarded Output Packets           = 7
  Output Packet No Route             = 0
  Reassembly Required                = 0
  Reassembly Successful              = 0
  Reassembly Failures                = 0
  Datagrams Successfully Fragmented  = 0
  Datagrams Failing Fragmentation    = 0
  Fragments Created                  = 0

C:\Users\Colin>netstat -sn -p IPv6

IPv6 Statistics

  Packets Received                   = 923
  Received Header Errors             = 0
  Received Address Errors            = 0
  Datagrams Forwarded                = 0
  Unknown Protocols Received         = 0
  Received Packets Discarded         = 35
  Received Packets Delivered         = 938
  Output Requests                    = 423
  Routing Discards                   = 0
  Discarded Output Packets           = 0
  Output Packet No Route             = 2
  Reassembly Required                = 0
  Reassembly Successful              = 0
  Reassembly Failures                = 0
  Datagrams Successfully Fragmented  = 0
  Datagrams Failing Fragmentation    = 0
  Fragments Created                  = 0

 

[TheLostSwede]

IPv4 Statistics

  Packets Received                   = 2590038
  Received Header Errors             = 0
  Received Address Errors            = 0
  Datagrams Forwarded                = 0
  Unknown Protocols Received         = 0
  Received Packets Discarded         = 3977
  Received Packets Delivered         = 2689915
  Output Requests                    = 1194798
  Routing Discards                   = 0
  Discarded Output Packets           = 4578
  Output Packet No Route             = 19
  Reassembly Required                = 0
  Reassembly Successful              = 0
  Reassembly Failures                = 0
  Datagrams Successfully Fragmented  = 0
  Datagrams Failing Fragmentation    = 0
  Fragments Created                  = 0

 

[TheLostSwede]

I just realised that my Netgear GS110EMX has a built in cable test, ran it, came out ok. I guess it's a bit of a basic test, but it seems the cable should be ok.

 

[degrub]

i recall those only pick up on miswired/shorted or broken wire (open) situations, not the quality of a connection.
What tests does this one do ?

 

[TheLostSwede]

That seems to be it, nothing too special.

 

[ColinTaylor]

That seems to be it, nothing too special.

According to the (minimal) information in the manual it can detect the distance down the cable where the fault has occurred. So it's slightly more sophisticated than just a continuity tester.

 

[TheLostSwede]

Ok, I have to apologise to everyone that's tried to help here, I found the issue, it's not the cabling...

Turns out the updated version of Aquantia's AQtion Command Center was somehow doing something weird on my PC that prevented me from getting the full bandwidth. It just happened to coincide with me changing things around, so I presumed it was a hardware/cable issue. I just closed it on my PC, as I ran a speed test on another device in the same room and it was fine and so is my PC now.

Thanks everyone that tried to help though.

Upload still seems a bit wonky though, but not as bad as it was.