VMS Help LANCP, DEFINE, DEVICE, Qualifiers, /DLL  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /DLL=(enable-option, exclusive-option, size-option,
       knownclientsonly-option)

    Provides the MOP downline load service settings for the device.

    Note that defaults apply to creation of an entry in the device
    database. If an existing entry is being modified, fields not
    specified remain unchanged.

    You can specify the following keywords with this qualifier:

    o  enable-option

             ENABLE
             DISABLE (default)

       Specify ENABLE or DISABLE to indicate that MOP downline load
       service should be enabled or disabled for the device.

    o  exclusive-option

             EXCLUSIVE
             NOEXCLUSIVE (default)

       Specify EXCLUSIVE to indicate that no other provider of MOP
       downline load service is allowed on the specified LAN device
       at the same time as LANACP. Specify NOEXCLUSIVE to indicate
       that the LAN MOP downline load service can coexist with
       other implementations (in particular, the DECnet Phase IV
       implementation that operates the MOP protocol in shared mode).

    o  size-option

             SIZE=value

       Use SIZE=value to specify the size in bytes of the file data
       portion of each downline load message. The permitted range
       is 246 to 1482 bytes. The default value is 246 bytes, which
       should allow any client to load properly. Note that some
       clients may not support the larger size.

       The recommended size for better load performance and less
       server overhead is the largest size that results in successful
       loads of all clients. The 1482 value is derived from the
       maximum packet size for CSMA/CD (Ethernet) of 1518 bytes less
       the 802e header and CRC (26 bytes) and MOP protocol overhead
       (10 bytes).

       You can override the size on a per-node basis. See the DEFINE
       NODE and SET NODE commands for details.

    o  knownclientsonly-option

             KNOWNCLIENTSONLY
             NOKNOWNCLIENTSONLY (default)

       Specify KNOWNCLIENTSONLY to indicate that MOP downline load
       requests should be serviced only for clients defined in
       the LAN permanent node database. When NOKNOWNCLIENTSONLY is
       selected, LANACP searches the LAN$DLL directory for any images
       requested by clients that are not defined in the LAN permanent
       node database.