Replace the fixed post-first-rekey and post-second-rekey settle sleeps in
the rekey integration test, and the fixed-deadline baseline wait in the
interop test, with the deterministic wait_until_connected progress-aware
polling helper already used for the initial baseline convergence.
Each converted site fails fast with structured diagnostics when the mesh
is stuck and extends its deadline only while pairwise reachability is
still climbing, removing the wall-clock settle windows that produced
intermittent connectivity failures after a rekey.
The interop harness only tested a full mesh, where every pair is a direct
one-hop FMP link. That left multi-hop forwarding, routing, coordinate
handling, and mesh-size estimation untested across versions.
Add an opt-in multi-hop topology and three new checks:
- generate-configs.sh: FIPS_INTEROP_EDGES selects an explicit undirected
edge list instead of the full mesh, with symmetric peering, connectivity
validation (no isolated node, graph connected), and per-node degree plus
edge metadata in nodes.env. Unset means full mesh, unchanged.
- interop-test.sh: a --topology flag with a built-in multihop-3v-cycle
(six nodes, two of each version, one cycle, two leaves). The per-node
peer check now expects each node's adjacency degree rather than N-1, and
the all-pairs ping now also exercises cross-version forwarding over
non-adjacent pairs. Adds a control-differential data-plane continuity
stream across the rekey window (Phase 5b) and a strict plus/minus 25
percent mesh-size convergence check (Phase 7).
- interop-stress.sh: forward --topology through to the per-rep driver
(mutually exclusive with a positional node-spec).
Phase 1 makes the strict retrying ping authoritative. The convergence
detector (one fully-clean, no-retry sweep of every directed pair) is now an
advisory settle-wait whose timeout is non-fatal; the strict retrying ping
decides pass/fail, matching how the post-rekey phases already work. Under
packet loss a clean no-retry sweep of a large mesh is statistically unlikely
even when the mesh is healthy (30 pairs at 2 percent loss leaves only about
55 percent of sweeps clean), so the detector otherwise falsely failed runs
whose strict ping reported full reachability. CONVERGENCE_TIMEOUT is now
env-overridable and defaults to 90s for larger meshes under loss.
Full-mesh runs are unaffected. Validated end-to-end with the
multihop-3v-cycle topology across three versions: all 30 directed pairs
reachable including multi-hop routed pairs, zero data-plane loss through
both rekey cutovers, and mesh-size converging to the true node count on
every node.