/sys$common/syshlp/helplib.hlb LANCP, DEFINE, NODE, Qualifiers, /ADDRESS  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /ADDRESS=node-address
       /NOADDRESS (default)

    Associates a LAN address with the node name. Specify the address
    as 6 bytes in hexadecimal notation, separated by hyphens. The
    address does not have to be unique (as might be the case when the
    address is not known, so a nonexistent address is specified).

    If multiple node addresses are to be associated with a node name,
    each combination may be given as a node name with an extension,
    for example, VAXSYS.EXA for the EXA device on node VAXSYS, or
    VAXSYS_1 for the first LAN device on node VAXSYS.

    If you do not specify the /ADDRESS qualifier, the setting remains
    unchanged. The /NOADDRESS qualifier clears the field.