'No valid IP configuration available' on LAN

[sjb]

I have two mobile classrooms currently without working LAN connections. They are connected by a fibre optic cable to the main building. I have had the fibre connection checked and new media converters fitted on both ends. The network sockets have also been checked and are working. Computers in both classrooms are reporting 'unidentified network' and 'no valid ip configuration available' for the LAN connection. Both can connect to the server via Wifi. All other computers (same make and model) can connect to the network without any issues, and we have spare IP addresses available.

 

I have reinstalled drivers, reinstalled Windows, checked cables, had two external contractors in to look at it, and spoken to the technical support helpline of the computer manufacturer. I have run out of ideas!

 

If anyone has any suggestions I would be very grateful.

 

Thanks

 

Sue

[Joanne]

When you switch the sockets that the computers are plugged into, do they do the same thing?

 

Might need new network cards?

[3s-gtech]

Activity lights on the fibre SFPs/slots? VLAN configuration on those ports? Upstream switch fault, like a failing SFP slot?

[njc235]

Is the switch receiving an ip address?

[FN-GM]

I would use SPF's instead of media converters.

 

Anyway get 2 laptops, give them static IP addresses in the same subnet. Put one on each end of the media converter and see if they can ping each other. If they can't it will be the converters.

[Davit2005]

I've seen DLink Media convertors with an Auto/Force switch. With these media converters you need to Force if the physical connection is between the 2 media converters.

[karldenton]

Did you get to the bottom of this in the end?