Verified live that the pre-flight check added in the previous commit had a
real gap: a plain `ping <gateway>` from the Proxmox host succeeds via the
HOST's own routing table (which can have routes to a subnet through paths
the host alone knows about), even when the CONTAINER — attached via a plain
bridge with only a naive on-link default route — can never actually ARP that
gateway. Confirmed by creating a real test container on vmbr0 with
gw=192.168.8.2: the host-wide ping had said "reachable," but pinging from
inside the container showed 100% packet loss. Fixed by binding the pre-flight
ping to the specific requested bridge (`ping -I <bridge>`), which correctly
rejects vmbr0 for that gateway instead of false-positiving via the host's
broader routing table.
Also confirmed live: vmbr1 does exist and is up on strong (contrary to the
possibly-stale host doc), matching what romm/seanime's docs already said.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
dtoro
3f3de18b23