Final confirming run with GRACE=300 and every fix installed:
--all ALL PASS (T0 T3 T5 T8 T11 T12)
--hard ALL PASS (replace / deny / disable, each policy verified)
Second independent measurement of the hard failover, which is what makes the
figures trustworthy rather than anecdotal:
run 1 run 2
replace 26s 26s
deny 148s 141s
disable 21s 20s
`deny` sits at ~141-148s across both, so it is the AC's dead-peer behaviour
and not a one-off; GRACE=300 keeps roughly 2x margin.
Corrected an overclaim in PPPOE-HA.md while confirming it: the invariant row
read "AC never showed two simdsl sessions", and under session-control=disable
it did -- one live, one orphaned from the destroyed router. Only ever one LIVE
router dialled, which is the invariant that matters. Said so plainly rather
than leaving a table that reads better than the evidence.
Both were invisible to inspection and only appeared under the hard matrix:
the flap damper tearing down an established session via the lease it stopped
renewing, and a missing peers file being completely silent. The second has a
production edge worth spelling out -- an unsaved commit reverts on reboot and
takes pppoe0 with it, leaving a standby that can never take over while
looking perfectly healthy.
Full run green: baseline (one AC session, held by the VIP holder), clean
failover (pppoe0 moves in 26s, old master releases), 10 gig down (route falls to
pppoe0 and the LAN is back online in 5s), lease expiry (the guard hangs up), and
a missing peers file (NRestarts=0, no loop). Evidence in
labsim/wan-failover-evidence/.
The 10 gig test found a genuine bug in vrrp-wan-health, not in the sim. GRACE
was measured from PROMOTION, so an established master had no grace at all --
after hours of uptime `now - since` far exceeds any window. The first moment
bond0.53 went down while pppoe0 was mid-redial, the master failed its own check,
shed every VIP, and the peer inherited the same WAN outage and did the same. A
brief WAN blip would have flapped the production pair. The stamp is now
refreshed on every healthy tick, so grace measures time since the box last
demonstrably HAD a WAN -- survivable wherever the gap happens, not only just
after a promotion.
Three harness bugs, all the same shape, all of which produced a confident wrong
answer before being caught:
- waiting for "exactly one pppoe0 holder" returns INSTANTLY during a handover,
because it was already true. The useful question is who holds it.
- judging connectivity on a single ping 20s after a link drop reported an
outage that had already healed. Poll, do not sample.
- `-o PreferredAuthentications=password` suits the routers but not the Alpine
LAN VMs, whose sshd offers keyboard-interactive: ssh exited 255 before
running anything and the test read that as "the LAN lost the internet". A
tcpdump on the router showed the pings leaving pppoe0 NATed to
198.51.100.117 and the replies coming back the whole time. An exit code that
can mean "the network is broken" or "I could not log in" is not a
connectivity test, so the check now asserts on what the guest reported.
That last one is why the harness asks the routers and the access concentrator
rather than a client, and why it refuses to run at all while either router still
has a default route via eth2 -- the libvirt-NAT scaffold answers connectivity
checks the WAN under test would have failed.
Still to run: hard failover (destroy the master), and the session-control
replace/deny/disable axis that brackets Vodafone's unknown behaviour and sets
the final GRACE. Nothing applied to production.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DMVzWZgiKW2wquf5z8S1yH
