Cable fault?

[AST]

Hi everyone,

 

Have a strange issue where an Ethernet point (installed summer 2016), allows WOL commands to wake the machine plugged into it (switch has connection/data lights on the port at this stage), but once machine switches on and moves through BIOS, the point goes dead with no lights on switch for that point.

 

If I plug any powered on machine into the point, that machine does not regain network connection and if I plug the original machine in to a different point, that machines connects to the network.

 

I have tried different cables from patch panel to switch, changed to different switch ports, re-punched the socket and still the same.

 

Anyone have any ideas on what else I can try without running a whole new cable!

 

Thanks

 

Adam

Edited January 17, 2017 by AST

[ITGURU]

Faulty Switch Port maybe? have you moved the patch to another port on the switch?

Occasionally we get a PC where it will boot, but won't log on and if you go on local it says unidentified network.

As soon as the switch port is moved, it immediately finds the network and gets an IP.

 

POE doesn't need an IP to boot, jut MAC address.

[Katy]

Have you tried running a cable tester on the port? Also have you tried re-punching at the patch panel as well as the socket? (especially if it's #1 or #24 on a panel they are usually under quite a bit of stress from the cable bunch).

 

We've also had PCs suddenly refuse to work unless you change switch port, then all is fine, but you said you've tried that.

 

Is it set to Auto negotiate on the PC? It may be that it does the WOL running at 10Mbps and then when in Windows tries to go full gigabit and fails (since gigabit needs all 4 pairs).

[Cazale]

Sounds like you've pretty much eliminated everything except the switch > port cable.

 

My money would be on one or two of the strands being nicked or snapped (the WOL magic packet is just a series of frames with a 4 digit hex-code followed by the MAC address, it doesn't require two-way communication). Have you tested the cable with a cable tester?

 

You're not using an Ethernet splitter anywhere are you? They cause all sorts of issues (won't work at all on gigabit or above, and drop 100mb down to half-duplex).

Edited January 17, 2017 by Cazale

[AST]

Thanks Katy and Cazale. I hadn't tried a slower speed and it works. Going to re-punch the patch panel after school, and hope that is all it is, if not, will leave the machine set to 100Mbps.

 

Thanks again

 

Adam