The sim's routing config existed only as running state on the VMs. It was
applied by hand over SSH, so rebuilding a VM lost the rehearsal and nothing
recorded why any of it was shaped the way it was. The two ISP VMs were not
referenced anywhere in the repo at all.
sim-net-config.py generates all four roles; sim-net-apply.sh applies them over
the serial console, or diffs them against the running VMs. Verified reproducing
live state exactly before committing: primary 40/40 commands, secondary 16/16,
isp-dhcp 19/19, isp-pppoe 21/21.
Carries the reasoning that was previously nowhere: RFC 8212 needing policy in
both directions or the session carries zero prefixes; probe targets that must
not double as system name-servers; default-route-distance 210 rather than
no-default-route, which blanks new_routers and hands the default route to the
backup line; and the WI-8 bootstrap bug that pinned /32s fix.
Dropped a stale `pppoe-server interface eth0` on isp-pppoe (a NIC that does not
exist there) so a green drift check stays meaningful.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DMVzWZgiKW2wquf5z8S1yH
