Use the set command to modify one or more attributes of an
    entity. For example:

    ncl> set node 0 osi transport delay factor=6,delay weight=10

    modifies two characteristics of the OSI Transport entity. If
    you specify more than one characteristic in a set command, use a
    comma to separate each characteristic and its value.

    If you specify a characteristic name, but no value, the
    characteristic is set to its default value; for example:

    ncl> set node 0 osi transport delay factor

    sets delay factor to its default value, 4.

    Use set to give a value to a characteristic whose value is a set,
    for example:

    ncl> set node 0 osi transport cons filters={filter_2,filter_3}

    but note the difference between this command and:

    ncl> add node 0 osi transport cons filters={filter_2,filter_3}

    The set command gives the cons filters characteristic a set value
    with two components: filter_2 and filter_3; if the set previously
    had other values, these are lost. The add command, on the other
    hand, adds the values filter_2 and filter_3 to whatever values
    the characteristic already has; any other current values are
    retained.

    To specify the empty set (that is, a set with no values), specify
    { } as the value.

    The set of attributes called characteristics can be
    changed by direct management commands and not by the system or
    indirect commands. For example, it may be changed by the set
    command, but not by the create or enable commands. However, some
    characteristics are read-only and never change.  Each entity section
    gives complete information about the entity's characteristics, if any,
    and explains if and how they are modified.

    Sequences, sets, and similar constructed data types must be
    explicitly stated in a set command.

    There are certain restrictions on the use of set to modify
    characteristics:

    o  Some characteristics can be modified only while the entity is
       disabled.

    o  A few characteristics can be modified only while the entity
       is disabled, and can then have only their value increased, not
       decreased.