ratively prohibited, destination is beyond the scope of the source address, the destination address is unreach- able, the source address failed ingress or egress filtering policy, or the router has a reject route to a destination. A destination node typically generates a Destination Unreachable message only when the destination port is not in use [56]. Packet Too Big A router that is unable to forward a packet because the packet is too big to fit in the next hop link sends an ICMPv6 Packet Too Big to the packet originator and with the same Introduction to IPv6 Table 3.2 ICMPv6 messages types ICMPv6 message Content in brief Error: Destination Unreachable Various reasons for unreachability [56] Error: Packet Too Big MTU of the link packet did not fit [56] Error: Time Exceeded Timeout or the hop count exceeded [56] Error: Parameter Problem Incomprehensible IPv6 parameter [56] Error: Private experimentation Depends on experiment [56] Error: Private experimentation Depends on experiment [56] Error: Reserved for expansion Reserved for the future [56] Echo Request Identifier for the Echo request [56] Echo Reply Echo request's identifier [56] Multicast Listener Query See Section 3.2.4 [44] Multicast Listener Report See Section 3.2.4 [44] Multicast Listener Done See Section 3.2.4 [44] Router Solicitation See Section 3.4 [41] Router Advertisement See Section 3.4 [41] Neighbor Solicitation See Section 3.4.4 [41] Neighbor Advertisement See Section 3.4.4 [41] Redirect Message See Section 3.4 [41] Router Renumbering Commands for router renumbering [60] Node Information Query Information that is being queried [53] Node Information Response Response data to the query [53] Inverse Neighbor Discovery Solicitation See Section 3.4.4 [61] Inverse Neighbor Discovery Advertisement See Section 3.4.4 [61] Version 2 Multicast Listener Report See Section 3.2.4 [45] Home Agent Address Discovery Request See Section 3.7.2 [35] Home Agent Address Discovery Reply See Section 3.7.2 [35] Mobile Prefix Solicitation See Section 3.7.2 [35] Mobile Pr