Library /sys$common/syshlp/nclhelp.hlb set, routing, generate_checksums  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Support: All
    Default: False         Value: True or false

    If true, specifies that checksums are generated for data, error
    report, and ES-IS PDUs initiated by this node. If false, these
    checksums are not generated. It is strongly recommended that,
    for performance reasons, you use the default value (indicating no
    checksum generation).