Tim Chase on Nostr: Correct. Using dummy values the config looks something like host * ...

Correct. Using dummy values the config looks something like

host *
ServerAliveInterval 55

host example
# HostName 198.51.100.32
HostName example.com
Port 2345
User gumnos
IdentityFile ~/.ssh/example

and I invoke with

$ ssh example

If I move the "#" to comment out the HostName with the name, uncommenting the HostName with the IPv4 address, it hangs after that IP_TOS 0x48 line.