3 ms·

Is computing a hash over 4x4bytes (+1 protocol bit) really faster than looking up an address (that is only 4bytes long, btw) in an optimized routing table ? Th

• tptacek 17y ago
  Yes, because every address seen by the router isn't in some simple lookup table in the router, unlike the flow table (or the CEF table or whatever your hardware has). That's not to say this is a huge win --- I don't think it is --- but yes, flow lookups are a simpler problem than per-packet routing and per-packet N-dimensional classification.