As others have mentioned, this is not often a problem because routing is normally fairly stable (at least compared to the lifetime of a typical connection). For

As others have mentioned, this is not often a problem because routing is normally fairly stable (at least compared to the lifetime of a typical connection). For longer lived connections (e.g. video uploads), it’s more of a problem. Also, there are a fair number of ASes that attempt to load balance traffic between multiple peering points, without hashing (or only using the src/dst address and not the port). This will also cause the problem you described. In practice it’s possible to handle this by keeping track of where the connections for an IP address typically ingress and sending packets there instead of handling them locally. Again, since it’s a few ASes that cause problems for typical connections, is also possible to figure out which IP prefixes experience the most instability and only turn on this overlay for them.