6.1 USER DATAGRAM PROTOCOL - UDP

The User Datagram Protocol (UDP) is specified in [TRANS:1].

A router that implements UDP MUST be compliant, and SHOULD be unconditionally compliant, with the requirements of [INTRO:2], except that:

• This specification does not specify the interfaces between the various protocol layers. Thus, a router's interfaces need not comply with [INTRO:2], except where compliance is required for proper functioning of Application Layer protocols supported by the router.

• Contrary to [INTRO:2], an application SHOULD NOT disable generation of UDP checksums.

DISCUSSION

Although a particular application protocol may require that UDP datagrams it receives must contain a UDP checksum, there is no general requirement that received UDP datagrams contain UDP checksums. Of course, if a UDP checksum is present in a received datagram, the checksum must be verified and the datagram discarded if the checksum is incorrect.