Even unsuccessful SSH attempts can have operational costs, though. The machine still accepts the TCP connection and does the SSH handshake. If I’m running a ser

Even unsuccessful SSH attempts can have operational costs, though. The machine still accepts the TCP connection and does the SSH handshake. If I’m running a server and I’m billed by data usage or by vCPU minutes, I don’t want to waste my allotted resources by making it easy for every half-baked crawler around the world to make connections to my machine. Using a non-default port cuts down those numbers significantly. Sure, a targeted attack won’t be thwarted, but at least the server is not being DDoS’ed anymore.