[mbreese]

Isn’t there a host SSH key involved?

The server itself may have been physically breached, and if so you can’t trust anything. But, if your host key matches, you should be confident that at least you’re logging into the correct machine (there was no IP takeover).

[akerl_]

If the server was breached, what stops somebody from copying the host key to their new system.

[mbreese]

True, but in that case, I think it would still be difficult to swap in a completely new system into the network (with your IP) with your old private host key.

(Without a physical breach... if that happens, all bets are off).