The link died when ESH lost its public IP during the fiber cutover. Two
independent causes, and the second would have defeated the obvious fix:
- phase1 ana-to-eshudm was type static, pinned to 70.181.90.232, an
address that no longer exists.
- nattraversal was disable, so ESP could not have crossed NAT even with
the peer IP corrected. pfi-ana-nh3 shares that setting and survives
only because NH3 is publicly addressed, which is why the two tunnels
diverged.
FortiOS refuses `set type dynamic` on an existing tunnel -- "Cannot
change tunnel type once configured" -- and rolled back cleanly, so the
fix could not be an edit. Rather than delete and recreate, which
cascades into the phase2, two static routes and ten policies, the
replacement was built alongside: new phase1+phase2 ana-eshudm-dyn
(type dynamic, ikev2, aes256-sha1, dh14, NAT-T on, PSK read from the ESH
UDM API so neither side needed a new key), static route id 10 at
distance 20, and two consolidated multi-zone policies 73/74. The old
tunnel is left in place, dead and harmless, as rollback.
Verified up: ana-eshudm-dyn_0 97.170.236.56:4500 selectors 1/1 -- the _0
suffix is a dialup child, :4500 is NAT-T, and the address is the
carrier's, which is precisely what could never have been pinned. ESH
reaches all four colo hosts at 40-56ms, the colo reaches all three ESH
hosts, and traceroute drops from eight hops leaking into the carrier
network to three hops fully encapsulated.
Config was backed up before any write (1.17MB, 36903 lines, off-box).
Residual fragility recorded: the UDM's ipsec_local_ip demands a literal
address -- empty is rejected as api.err.InvalidPayload -- so it still
needs updating when the fiber changes ESH's WAN address. The gateway end
is now address-agnostic; the UniFi end is not.
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