RFC4301 Section 7.1 says: "7.1. Tunnel Mode SAs that Carry Initial and Non-Initial Fragments All implementations MUST support tunnel mode SAs that are configured to pass traffic without regard to port field (or ICMP type/code or Mobility Header type) values. If the SA will carry traffic for specified protocols, the selector set for the SA MUST specify the port fields (or ICMP type/code or Mobility Header type) as ANY. An SA defined in this fashion will carry all traffic including initial and non-initial fragments for the indicated Local/Remote addresses and specified Next Layer protocol(s)." But for IPv6, fragment is treated as a protocol. Would the following patch be acceptable to catch protocol transported in fragmented packet? In IPv4, there is no problem. Signed-off-by: Nicolas Dichtel