University of St Andrews, UK Independent, USA University of Aberdeen, UK The Identifier Locator Network Protocol (ILNP) for IPv6 is described in Experimental RFCs 6740-6744. ILNP defines the use of an Identifier-Locator Vector (I-LV) with a zero value L64 value and a relevant Node Identifier (NID) value in place of an IPv6 address in the pseudo-header for transport protocol checksum computations. However, as TCP and UDP predate ILNP, this change causes TCP and UDP checksum values to be generated for ILNP flows that are different to the same flows on IPv6. This document changes the checksum computation for TCP and UDP with ILNP so that the checksum values are the same for ILNP and IPv6. This document updates the checksum processing for TCP and UDP described in RFC6740 and RFC6741, and the way the checksum processing should be applied for TCP and UDP in RFC6748.