/DLL or MOPDLL=(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 and DECnet
       Plus implementations that include MOP support).

       Note that when you select NOEXCLUSIVE, LANACP responds only
       to MOP downline load requests directed to nodes defined in the
       LAN node database.

    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 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 you select
       NOKNOWNCLIENTSONLY, LANACP searches the LAN$DLL directory
       for any images requested by clients that are not defined in
       the LAN node database.

       Note that this option is not available when NOEXCLUSIVE mode
       has been selected. In NOEXCLUSIVE mode, LANACP services MOP
       downline load requests only for clients defined in the LAN
       node database.