Steven M Bellovin writes:
Jim Shankland <nanog@shankland.org> wrote:
(2) Getting this kind of throughput seems to depend on a fast physical layer, plus some link-layer help (jumbo packets), plus careful TCP tuning to deal with the large bandwidth-delay product. The IP layer sits between the second and third of those three items. Is there something about IPv6 vs. IPv4 that specifically improves perfomance on this kind of test? If so, what is it?
I wonder if the router forward v6 as fast.
In the 10 Gb/s space (sufficient for these records, and I'm not familiar with 40 Gb/s routers), many if not most of the current gear handles IPv6 routing lookups "in hardware", just like IPv4 (and MPLS). For example, the mid-range platform that we use in our backbone forwards 30 Mpps per forwarding engine, whether based on IPv4 addresses, IPv6 addresses, or MPLS labels. 30 Mpps at 1500-byte packets corresponds to 360 Gb/s. So, no sweat. Routing table lookups(*) are what's most relevant here, because the other work in forwarding is identical between IPv4 and IPv6. Again, many platforms are able to do line-rate forwarding between 10 Gb/s ports. -- Simon, AS559. (*) ACLs (access control lists) are also important, but again, newer hardware can do fairly complex IPv6 ACLs at line rate.