Why a backup path
A single private circuit to a site is a single point of failure. A second circuit over a diverse path is ideal but expensive for smaller sites.
The affordable option
Add an internet connection at the site and build an IPsec tunnel to a Peer1IX edge location. It lands on the same private network as the primary circuit.
Routing
Run BGP over both the circuit and the tunnel. Prefer the circuit; if it fails, routes over the tunnel take over automatically.
Capacity expectations
The tunnel may offer less bandwidth or more variable performance. Prioritise critical applications during failover.
Test it
Simulate circuit failure periodically to confirm the tunnel comes up and carries traffic.
