Solved

Netgear GS748TPS Switch not communicating with network over fibre

Posted on 2012-04-13
8
1,035 Views
Last Modified: 2012-06-21
For the last couple of months we have had a Netgear GS748TPS happily communicating with our core switch via a fibre link.

After a powerdown of all our equipment it stopped working properly.

The port with the Fibre module lights up green and and flashes away to show that it is communicting with the core switch (Netgear GSM7328FS), but it is not pingable and any client plugged into the GS758TPS switch cannot contact anything else on the network.

If I remove the fibre connection and try a Cat5e connection, the switch becomes pingable and the clients attached can communicate with the rest of the network.  This only happens when connecting with the Fibre.

Things we have tried:

* Factory reset the switch and set it up from scratch
* Update Firmware
* Change the switch for another brand new identical switch (we have a few at the moment as we are refreshing a lot of our equipment)
* Plugging the switch directly (with a 2m fibre patch cable) into the core switch

Whatever I try, the same thing seems to happen.....the lights flash either end to show communication, but the switch or any of the clients connected cannot communicate with the rest of the network.

If I change the fibre uplink or cat5, it works fine.

As we have changed the switch, it makes me thing that it is a setting on the GSM7328FS core switch, but I dont know what this might be as it has been working fine for the last couple of months.

Any help appreciated!
0
Comment
Question by:stalbansschool
  • 4
  • 3
8 Comments
 
LVL 17

Expert Comment

by:TimotiSt
ID: 37842938
I'd guess one of the SFP transceivers burned out. I had cases where the link LED came online, only it wasn't passing traffic, or only at ~4Mbps with lots of errors.

Tamas
0
 

Author Comment

by:stalbansschool
ID: 37842979
Sorry, forgot to say that we also have a load of SFP tranceivers and we have tried replacing those as well
0
 

Author Comment

by:stalbansschool
ID: 37842989
Some more experimenting seems to also suggest that connecting via CAT5 does NOT work on the core switch as I incorreclty said in my first post.

However, if I connect via CAT5 to a different switch further down the chain, this does work.
0
 

Author Comment

by:stalbansschool
ID: 37843128
As a side peice of information which is probably not relevant, I cannot seem to save the 'local' time on the switch.

If I try to configure the time and apply it, it resets back to its default date (sometime in 2008) after the switch reboots.

Not sure if this is relevant...
0
Network it in WD Red

There's an industry-leading WD Red drive for every compatible NAS system to help fulfill your data storage needs. With drives up to 8TB, WD Red offers a wide array of solutions for customers looking to build the biggest, best-performing NAS storage solution.  

 
LVL 17

Accepted Solution

by:
TimotiSt earned 500 total points
ID: 37845076
Idea: maybe it's a spanning tree issue? Check the STP status on the relevant ports, with and without another switch in-between.
0
 
LVL 11

Expert Comment

by:Khandakar Ashfaqur Rahman
ID: 37845465
Switch off the fiber module.

Then install Packet Analyzer into a pc like wireshark.Mirror your switchport and start PKT monitoring.
http://www.wireshark.org/download.html

Now you turn on Fiber module.Analyze wireshark pkt.
0
 

Author Closing Comment

by:stalbansschool
ID: 37850511
Yes! Thank you!

By disablling STP on the switch, it is now working correctly.

Great suggestion, thanks!
0
 
LVL 17

Expert Comment

by:TimotiSt
ID: 37850728
While this may be a good temporary solution, if you had STP issues, there might be a loop or something in your network.
You should check everywhere for rogue switches/connections/whatever, and fix your network so it works again with STP. It's a good protocol to safeguard against problems.

Tamas
0

Featured Post

Maximize Your Threat Intelligence Reporting

Reporting is one of the most important and least talked about aspects of a world-class threat intelligence program. Here’s how to do it right.

Join & Write a Comment

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…
Managing 24/7 IT Operations is a hands-on job and indeed a difficult one. Over the years I have found some simple tips and techniques to increase the efficiency of the overall operations. The core concept has always been on continuous improvement; a…
Here's a very brief overview of the methods PRTG Network Monitor (https://www.paessler.com/prtg) offers for monitoring bandwidth, to help you decide which methods you´d like to investigate in more detail.  The methods are covered in more detail in o…
This video gives you a great overview about bandwidth monitoring with SNMP and WMI with our network monitoring solution PRTG Network Monitor (https://www.paessler.com/prtg). If you're looking for how to monitor bandwidth using netflow or packet s…

744 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

Need Help in Real-Time?

Connect with top rated Experts

14 Experts available now in Live!

Get 1:1 Help Now