Telematics Chapter 6: Network Layer - Freie Universität Berlin

IPv6 Path MTU Discovery
● Path MTU Discovery
● MTU: Maximum Transmission Unit
● Maximum packet size in octets, that can be conveyed in one piece over a link
● Path MTU: The minimum link MTU of all the links in a path between a source
node and a destination node
● Path MTU Discovery Process
● The originating node assumes the Path MTU is the MTU of the first hop in the
path.
● A trial packet of this size is sent out.
● If any link is unable to handle it, an ICMPv6 Packet Too Big message is returned.
● The originating node iteratively tries smaller packet sizes until it gets no
complaints from any node, and then uses the largest MTU that was acceptable
along the entire path.
Univ.-Prof. Dr.-Ing. Jochen H. Schiller ▪ cst.mi.fu-berlin.de ▪ Telematics ▪ Chapter 6: Network Layer
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