Designing Hardware-Assisted Forwarding Planes for Constant-Time Network Recovery
Large networks are built with redundancy everywhere. Links are duplicated. Routers have alternate paths. Routing protocols continuously calculate multiple ways to reach the same destination.
Yet redundancy alone does not guarantee fast recovery.
When a link or node fails, the network still has to detect the failure, select an alternate route, update the forwarding table, program the hardware, and resume traffic. In traditional routing architectures, that process often scales with the number of affected prefixes. The larger the routing table becomes, the longer recovery can take.
That creates an uncomfortable engineering reality. A network may become more capable as it grows, but also slower to recover.
Hardware-assisted prefix-independent convergence changes that relationship. Instead of recomputing and rewriting every affected route after a failure, the forwarding plane can pre-install backup next-hops and switch traffic through a shared indirection object. The recovery operation becomes a pointer update rather than a route-table rewrite.
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