Downtime with unet responding to pings

This morning, unet was down (thanks to @ymasur for reporting this). The machine was still running, responding to pings, but we couldn't log in or even access the machine locally. A reboot resolved this, which unfortunately the reason for this glitch is unknown.

In addition, we connected again the KVM, which at some point appeared not to be working. This was resolved by moving the machine meknes from port 4 to 3, as port 3 was unoccupied. It is possible the port 4 of the KVM is dysfunctional, or that the KVM doesn't expect to have an unused port (3) in between two used ports (2 and 4).