Checksum (2 bytes)

Protocol: OSPF OSPF PCI

PDU Part: common header / used by all OSPF packet types

Field: checksum

Length: 2 bytes

Contents: checksum.

The standard IP checksum of the entire contents of the packet, excluding the 64-bit authentication field. The checksum is calculated as the 16-bit one's complement of the one's complement sumof all the 16-bit words in the packet, excepting the authentication field. If the packet's length is not an integral number of 16-bit words, the packet is padded with a byte of zero before checksumming.