Solved

Perfect crosstalk?

Posted on 2013-01-03
3
324 Views
Last Modified: 2013-01-27
Weekend fun:

(I know it's not best practice, don't tell me... :) )
Setup: only one cat5 (solid core, around 50-60m run) copper to a classroom, need access for lecturer PC and wireless AP. Instead of small managed switch, I went with a passive splitter.
AP receives 24V POE on far end after splitter.
AP immediately falls back to and stays on 10meg connection, error counter on 0 after days, appears to be working perfectly, wireless clients happy.
Fun part: sometimes the MAC of the AP appears on the 'wifi vlan' port (good thing), and also on the 'student vlan' port where the split cable PC is.
Double-checked, vlans are not bridged together in the area.

So: what's your guess? Perfect, full-frame crosstalk on the splitted cable, or the otherwise perfectly reliable 3Com 4400 box started bleeding between vlans, or other?

Cheers,
Tamas
0
Comment
Question by:TimotiSt
  • 2
3 Comments
 
LVL 45

Assisted Solution

by:Craig Beck
Craig Beck earned 300 total points
ID: 38747443
Crosstalk wouldn't make a MAC address appear on a different port.  This would only be caused by a bridge or loop.

Do any of your student clients have wired and wireless connections back to the same switch?  If so, make sure none of them have inadvertently bridged their NICs.

Also, make sure your STP is working properly.
0
 
LVL 17

Accepted Solution

by:
TimotiSt earned 0 total points
ID: 38804935
Okay, got this one:
The Cat5 run in the wall is patched up somewhere, where it has strange cable shorts. Pins 1,2,3 and 6 are not shorted to each other, but they are to random other pins, so it's a mess...
Couldn't originally debug with my cheap cable tester...
Anyways, it kinda works with only one 100Meg connection, without a passive splitter. But I'll definitely need a new cable run...

Tamas
0
 
LVL 17

Author Closing Comment

by:TimotiSt
ID: 38823762
Managed to debug the cable.
0

Featured Post

PRTG Network Monitor: Intuitive Network Monitoring

Network Monitoring is essential to ensure that computer systems and network devices are running. Use PRTG to monitor LANs, servers, websites, applications and devices, bandwidth, virtual environments, remote systems, IoT, and many more. PRTG is easy to set up & use.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

The worst thing when starting a new job is when the previous Network Administrator left behind no documentation. How do you get into the devices? If you've been in this situation or just accidently mistyped your password, this article will hopefully…
I see many questions here on Experts Exchange regarding switch port configurations and trunks. This article is meant for beginners in the subject to help to get basic knowledge about Virtual Local Area Network (VLAN (http://en.wikipedia.org/wiki/Vir…
This tutorial gives a high-level tour of the interface of Marketo (a marketing automation tool to help businesses track and engage prospective customers and drive them to purchase). You will see the main areas including Marketing Activities, Design …
Established in 1997, Technology Architects has become one of the most reputable technology solutions companies in the country. TA have been providing businesses with cost effective state-of-the-art solutions and unparalleled service that is designed…

803 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question