The pre-VESPA wireless GW campus solution offered redundancy by means of having primary and secondary wireless GWs that can be configured in the Access Points (APs). APs monitor the primary tunnel's health by means of periodic ICMP messages, and switch to the secondary tunnel when the primary becomes unreachable, and traffic convergence is delayed until this failover happens.

Adjacency sharing is a feature which deduplicates FEC to avoid installing identical FECs in hardware. Often this applies to Equal Cost Multi Path (ECMP) FECs, which are generally a much more scarce resource. Hierarchical FECs are not supported with adjacency sharing.

TOI EOS 4.35.2F Adjacency Sharing Host Route Scaling Selective Adjacency Sharing