Path Mtu (Pmtu) Discovery - HP 8200zl Configuration Manual

Introduction to IPv6

Path MTU (PMTU) Discovery

2-16

Path MTU (PMTU) Discovery

IPv6 PMTU operation is managed automatically by the IPv6 nodes between
the source and destination of a transmission. For Ethernet frames, the default
MTU is 1500 bytes. If a router on the path cannot forward the default MTU
size, it sends an ICMPv6 message (PKT_TOO_BIG) with the recommended
MTU to the sender of the frame. If the sender of the frame is an IPv6 node
that supports PMTU discovery, it will then use the MTU specified by the router
and cache it for future reference.
For related information, refer to:
■ RFC 1981: "Path MTU Discovery for IP version 6"