Investigated why the operator couldn't get past "no DNS/connectivity" across
multiple retries even after Nomos correctly diagnosed and fixed the gateway
(192.168.8.1 -> 192.168.8.2). It still failed. Root cause, confirmed from
strong's own documented network topology: on `strong`, vmbr0 physically
bridges only to 192.168.178.0/24 — the 192.168.8.0/24 service network is
reached via a Fritz!Box static route, not a local bridge. A container
attached to vmbr0 can never reach a 192.168.8.x gateway no matter which
address in that range is picked; ARP for it just gets silently dropped
(matching the earlier hang symptom). The gateway was never the problem — the
bridge was. 192.168.8.0/24 is also segmented into /28 blocks each with their
own gateway (192.168.8.2 is only the .0-.15 block's gateway), so even a
correct bridge with a copy-pasted gateway from a different block would still
fail.
No amount of retrying with a different gateway guess could have fixed this —
the missing fact (which bridge reaches which subnet, and the per-/28 gateway)
isn't inferable from the subnet alone.
- pct_create gets a `bridge` param (was hardcoded to vmbr0) so a correct
bridge can actually be requested once known.
- Fast pre-flight: for any static IP, ping the gateway from the target HOST
before creating anything. Was: a bad config took a multi-minute hang (or,
after last commit's timeout fix, ~2min) before failing. Now: ~2 seconds,
with a message that explicitly says not to guess a different gateway in
the same subnet — find a real neighbor's config or use DHCP.
- SOUL.md: DHCP is now framed as the default, not a fallback; static IP
requires finding an existing LXC on the same host in the same /28 and
copying its bridge+gateway verbatim — inventing one is explicitly called
out as the failure mode that caused this exact incident.
- MCP tool schema: pct_create's params description now documents `bridge`
and the neighbor-copy rule directly in what the model reads at call time,
not just in SOUL.md.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
dtoro
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