The router resolves it to 10.0.0.2 at the DNS level and the remote URL
already carries :2222, so the alias was redundant everywhere and wrong on
mainframe, where it pointed at localhost. Verified: connecting with
-F /dev/null succeeds from both mainframe and system76.
Putting the whole ssh config in common/ was wrong twice over. It mapped
git.rcjohnstone.com to localhost:2222, which is only true on mainframe
where Gitea runs -- on system76 it broke git entirely. And it replaced a
77-line file holding 13 personal host aliases (storagebox, several
forwarded localhost ports, older work hosts) with a five-entry fleet list.
common/ssh/config now Includes ~/.ssh/config.local first, so host entries
win on the first-value-obtained rule, and carries only the fleet aliases.
Each host keeps its own list; system76's is restored verbatim.
connor