I dont have much experience here, but after the link
goes down, did you try to connect to that port using a
laptop? I had soemthing simmilar once and it took me
one month to realize that the main switch was shuting
donwn the port as a result of a security policy.
Thanks for that suggesstion. I tried and found out, that its not due to a shut down port on the switch.
When connecting a computer to the same port afterwards, the port works perfectly.
Hmm. Gotta check for something else.
Cheers,
/dev/loop