On 9/30/2017 9:30 PM, John Levine wrote:For an example how how we might improve v6 wonderfulness, see Geoff Huston's recent blog post on how badly v6 fragmentation works with large DNS responses like you get with DNSSEC: https://blog.apnic.net/2017/08/22/dealing-ipv6-fragmentation-dns/ draft-ietf-intarea-tunnels explains why all protocols that support any level of "self encapsulation" (e.g., X in X) always require fragmentation and reassembly at some layer. IPv6 fragmentation might not be the best way to support DNS over UDP*, but that's because of router vendors who (incorrectly) claim to support IPv6 while dropping valid IPv6 packets (e.g., fragments). Joe * an alternate approach is to fragment either at UDP or DNS; the former is being developed in tsvwg: draft-ietf-tsvwg-udp-options. Joe |