# Test 13 · VPN #1 dual-tunnel BGP failover

Date: 6 Aug 2026 (SGT)

Environment: school AWS account `427617722186`

Result: **PASS WITH MEASURED INTERRUPTION**

## Accepted configuration

- Dynamic VPN: `vpn-053c85ebeeb20c115`
- Ireland VGW: `vgw-02efe604037a218cf`, ASN `64512`
- Virginia strongSwan/Quagga router: ASN `65000`
- Tunnel 1 outside peer: `34.252.232.43`
- Tunnel 2 outside peer: `52.208.125.123`
- Both tunnels: IKEv2, AES-256, SHA-256, DH group 14, route-based 0/0
  selectors, BGP and one accepted route per AWS endpoint
- Inbound prefix filter: only `10.1.0.0/16`
- Outbound prefix filter: only `10.0.0.0/16`
- Deterministic preference: tunnel 1 local preference 200; tunnel 2 local
  preference 100; negotiated BGP hold time 9 seconds

## Baseline proof

Both BGP peers were established and each received one Ireland route. AWS
reported both tunnels `UP` with `AcceptedRoutes=1`. From Virginia test host
`10.0.1.224`, both current Ireland web nodes passed private tests:

- `10.1.1.119`: 4/4 ICMP, approximately 69 ms; HTTP 200
- `10.1.2.5`: 4/4 ICMP, approximately 70–93 ms; HTTP 200

## Controlled failure

The operator blocked only tunnel 1's outer peer on the Virginia router,
simulating loss of the preferred encrypted path while leaving tunnel 2,
instances, route tables and applications running. A 0.25-second continuous
private ping was retained throughout.

- Failure injection: `2026-08-06T01:36:30Z`
- BGP route selected tunnel 2 after: **11 seconds**
- Continuous probe: 160 sent, 129 received, 31 lost (**19% over the complete
  40-second observation window**)
- Approximate traffic interruption from probe loss: **7.75 seconds**
- Surviving peer remained established and carried `10.1.0.0/16`

The block was then removed. Tunnel 1 re-established automatically and the
higher local preference restored it as the selected route. Final private ICMP
returned 4/4 replies at approximately 69 ms.

## Claim boundary

This proves automatic routing convergence between two simultaneously
established BGP/IPsec tunnels. It does not prove zero-loss or sub-second
failover. The observed interruption is retained rather than hidden; it is
consistent with BGP/DPD detection and route convergence over an internet VPN.