[clue-talk] network issue

[Nate Duehr]

Dennis J Perkins wrote:
> Has anyone ever seen what happens if someone plugs a cable into two 
> ports on a switch?  This supposedly happened at work last week and 
> brought down the network.  The IT people confiscated all switches to 
> prevent this from happening again.  A rather drastic solution, 
> considering this is preventing me from hooking up PLCs to do system 
> testing since I don't have any spare network ports in the test area.

Yes.  It creates a Layer 2 loop.

If the switches are not total pieces of junk, they implement 
spanning-tree and one port gets locked out.

> IT claims that special switches tha

I assume that you were about to say that your IT group thinks switches 
of a quality high enough to understand proper spanning-tree are 
supposedly too expensive and unavailable to you?  If that's the case, 
they're taking the risk that a single cable plugged in wrong can bring 
down their network, and it's not a commercial quality network, IMHO.

Nate