Does anyone know of a KVM switch that is also a VNC (or other protocol like it) server?
We've always used Avocent and really like the built in web console:
I used a 16 port Startech IP KVM that supported the VNC protocol. I could VNC into the IP of the device and switch to the desired machine. It was a little clunky, but that could be because it was over a T1 that I was connecting. Connecting locally was acceptable, but that's about all you need to issue a ctrl-alt-del on a hung machine anyhow. I will try to find the exact device I used.
HERE is the link.
Depending on your configuration, you might be able to cobble together something using VNC in conjunction with Synergy, if the two machines are near each other. If you have Linux as your primary Synergy system I use QuickSynergy as the GUI to simplify things on my setup.
A quick Google search brought me to a page that listed a bunch of IP based KVM switches, which is what I believe you are looking for. I have not used them as they are pricey for my current needs, and back when I really needed them, they did not exist.
You could get one of these http://www.lantronix.com/it-management/kvm-over-ip/ and plug it into any KVM
One gatcha : your KVM will have to allow keyboard macros to allow you to change to diffrent KVM ports (it wouldnt work if you have to push a physical button on the KVM to flip to diffrent machines)