RFD 1101: Two SSH hosts only, DGX-Local and DGX-Remote
Problem
The DGX Spark shows up under more than one name across NVIDIA Sync and an SSH client: DGX-Local, DGX-Remote, and the raw hostname dgx-spark.local, which reads as a third machine if the naming rule is not written down anywhere.
Decision
Exactly two SSH hosts: DGX-Local (dgx-spark.local, at home) and DGX-Remote (100.93.124.59, over Tailscale, away). dgx-spark.local is not a third machine; it is DGX-Local’s own address, reached through ~/.ssh/config-cursor. An auto-guard script (scripts/install-dgx-ssh-guard.ps1, checked with npm run dgx:guard) restores the golden config templates when NVIDIA Sync or the editor’s own SSH settings drift, but never re-pairs NVIDIA Sync or deletes a host itself.
See DETAILS.md for every repair script, what each one touches, and the reverse-SSH setup from the DGX back to the Surface.