=== hard failover, session-control=replace, 2026-09-05T19:20:56+01:00 ===
master labsim-vyos2 (172.31.1.253) destroyed with virsh destroy -- no PADT sent.

-- survivor took over and dialled --
  172.31.1.252  holds_vip=yes wan_up=yes ppp_up=yes ppp_active=yes may_dial=yes role=master

-- AC: exactly one session throughout, from the survivor's MAC --
  ppp0 simdsl 198.51.100.121 calling-sid 52:54:00:e5:95:a2 active 00:07:01

-- returning router did NOT dial on boot (the gate) --
  ConditionResult=no  ActiveState=inactive  NRestarts=0  pppoe0 absent  may_dial=no
  AC session count after its return: 1

-- caveat --
  A VM restart recreates its taps, leaving the OVS bond holding stale members
  (lacp dead, VLAN 1 unreachable). Re-bonded via ovs_bond_router; the harness
  now does this automatically after virsh start.