Murphy at the Network and Service Management Summer School

I am just returning form the 2nd International Summer School on Network and Service Management. During some SNMP experiments, something interesting happened: A networking device used for the tests which has been silently running for years at the University of Twente suddenly went offline. We later found out that someone in Twente decided that today is the perfect day to move the box to another place…

Later on, during another lab sessions, we experienced a problem where packets originating form the notebooks of the summer school participants experienced high packet loss at the border router of our university, rendering ssh useless. There was no packet loss for ssh traffic originating from other locations so we worked around the problem by letting people ssh to other nodes first before they did connect to our machines. We also had the feeling that the packet loss increased with the number of concurrent ssh sessions originating form the summer school network. Of course, this problem did not happen before and this strange behavior apparently also did not affect any other sites…