What amazes me about mosh is how it handles transitions in and out of the private wifi network at my school. When I want to ssh to school machines from off campus, I generally need to use a VPN. Without the VPN the machines are unreachable: if I ping them, no packets are returned; ssh attempts fail. Using mosh, though, I've found that I can start a session at school and resume it off campus, no VPN necessary. This seems like magic to me. Can anyone explain how mosh does this?