ndd(1M)

NAME

     ndd - get and set driver configuration parameters

SYNOPSIS

     ndd [-set] driver parameter [value]

DESCRIPTION

     ndd gets and sets selected configuration parameters in  some
     kernel  drivers.  Currently,  ndd  only supports the drivers
     that implement the TCP/IP  Internet  protocol  family.  Each
     driver  chooses  which parameters to make visible using ndd.
     Since these parameters are usually tightly  coupled  to  the
     implementation,  they  are  likely to change from release to
     release. Some parameters may be read-only.

     If the -set option is omitted, ndd queries the named driver,
     retrieves the value associated with the specified parameter,
     and prints it. If the  -set  option  is  given,  ndd  passes
     value,  which  must  be  specified, down to the named driver
     which assigns it to the named parameter.

     By convention, drivers that support ndd also support a  spe-
     cial  read-only  parameter  named ``?'' which can be used to
     list the parameters supported by the driver.

EXAMPLES

     Example 1: Getting Parameters Supported By The TCP Driver

     To see which parameters are supported  by  the  TCP  driver,
     use the following command:

     example% ndd /dev/tcp \?

     The parameter name ``?'' may  need  to  be  escaped  with  a
     backslash  to  prevent its being interpreted as a shell meta
     character.

     The following  command  sets  the  value  of  the  parameter
     ip_forwarding in the dual stack IP driver to zero. This dis-
     ables IPv4 packet forwarding.

     example% ndd -set /dev/ip ip_forwarding 0

     Similarly, in order to disable IPv6 packet  forwarding,  the
     value of parameter ip6_forwarding

     example% ndd -set /dev/ip ip6_forwarding 0

     To view the current IPv4 forwarding table, use the following
     command:

     example% ndd /dev/ip ipv4_ire_status

     To view the current IPv6 forwarding table, use the following
     command:

     example% ndd /dev/ip ipv6_ire_status

ATTRIBUTES

     See attributes(5) for descriptions of the  following  attri-
     butes:

     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Availability                | SUNWcsu                     |
    |_____________________________|_____________________________|

SEE ALSO

     nca(1), ioctl(2), attributes(5), arp(7P),  ip(7P),  ip6(7P),
     tcp(7P), udp(7P)

NOTES

     The parameters supported by  each  driver  may  change  from
     release  to release. Like programs that read /dev/kmem, user
     programs  or  shell  scripts  that  execute  ndd  should  be
     prepared for parameter names to change.

     The ioctl()  command  that  ndd  uses  to  communicate  with
     drivers  is  likely to change in a future release. User pro-
     grams should avoid making dependencies on it.

     The meanings of many ndd parameters make sense only  if  you
     understand how the driver is implemented.