In this wiki entry disguised as a RFC 7872, “Observations on the Dropping of Packets with IPv6 Extension Headers in the Real World” highlights IPv6 Extension Headers are effectively unusable since internet providers are dropping IPv6 fragment and failing to support Extension Headers.
In IPv6, an extension header is any header that follows the initial 40 bytes of the packet and precedes the upper-layer header (which might be a transport header, an ICMPv6 header, or a notional “No Next Header”). – RFC 7045 Standards Track
In a present at IEPG, Fragmentation and Extension Header Support in the IPv6 Internet testing showed that practical usage of important IPv6 features is impossible with more failure rate greater than 50%:
- IPv6 Fragmentation – Failure rate: 47.68 %
- IPv6 Extension Header (8 bytes) – Failure rate: 52.53 %
- IPv6 Extension Header (1 KBytes) – Failure rate: 92.17 %
Fragmentation is Important
IPv6 Fragmentation is important to the future of internet services. The current 1500 byte
IPv6 has a minimum MTU of 1280 bytes but a maximum of 4GB (jumbogram).