Connected: An Internet Encyclopedia
A.1 Encapsulation of OSPF packets

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A.1 Encapsulation of OSPF packets

A.1 Encapsulation of OSPF packets

OSPF runs directly over the Internet Protocol's network layer. OSPF packets are therefore encapsulated solely by IP and local data-link headers.

OSPF does not define a way to fragment its protocol packets, and depends on IP fragmentation when transmitting packets larger than the network MTU. The OSPF packet types that are likely to be large (Database Description Packets, Link State Request, Link State Update, and Link State Acknowledgment packets) can usually be split into several separate protocol packets, without loss of functionality. This is recommended; IP fragmentation should be avoided whenever possible. Using this reasoning, an attempt should be made to limit the sizes of packets sent over virtual links to 576 bytes. However, if necessary, the length of OSPF packets can be up to 65,535 bytes (including the IP header).

The other important features of OSPF's IP encapsulation are:


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Connected: An Internet Encyclopedia
A.1 Encapsulation of OSPF packets