atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services Cabling Telephones Systems Wiring 568a or b configuration

It was the 258a standard that became 568b my fault, got them confused with 568a.

If the system was working with the mixed wiring and then suddenly stopped working, it is obviously not the wiring.

You need to some basic network troubleshooting.

1. With everything disconnected from the switch but the switch connected to the router, connect your laptop to the switch and see if you get on the internet. If you do, then start adding connections to the switch ports until you add one and you lose internet connection. Then troubleshoot that cable and the device or devices attached to it.

2. Be aware, (and this is the bane of network topology), one device that is throwing garbage on the network can bring down the whole network and make all devices on that network inoperative. It's called denial of service or DOS and can affect VoIP networks as well. Use process of elimination to detect the problem.

Rcaman

And once you identify the cable, make sure you test everything attached to it for the entire length such as supplementary switches and the attached devices. May be a hidden switch in a closet, under a desk, etc.

Rcaman is on track with this one. We once had the cleaning guys come in and do the floors strip, wax, polish and etc... They got into computer lab, disconnected all pc's, did what they had to with the floor, here came interesting part, they took initiative to hook everything back up. Needless to say they had one patch cord plugged into two network jacks and that's when the fun has begun. Following Monday we sure were in for a surprise, I got woken up bright and early and did not appreciated too much when someone was screaming in panic that there was no internet in the whole building.

It's called a 'Broadcast Storm'. A Denial of Service attack comes from the outside.

A simple cable plugged in between two switches on a network causing a loop to happen will cause a broadcast storm and will crash your network. There are several other simple things that can cause it too.


You have to find out if the network is working without the modem plugged in first. Otherwise, you'll just be chasing your tail.

Technically, a broadcast storm effectively causes a denial of service. The point here, is, that troubleshooting the OP's problem will require breaking down the system into segments that can be tested and verified.

Rcaman

Ah, the old cleaning lady syndrome. In my book, I promise to devote an entire chapter to that peculiar breed of trouble-maker. One or two of the stories will be X-rated, of course, but those were extremely rare occurrences. Right, Sam?... (nudge nudge wink wink)

Indeed they were, Arthur.

More on this later.

Sam

Arthur, I will be first in line to buy your book.

Having spent a couple days in Arthur's company at this year's TCI show in Lancaster, I can say I don't think I've ever been as awed by sheer telephonic knowledge and entertained by stories by anyone as much as I was with him.

Thanks, Mom.