ndd(1M)                                                             ndd(1M)




 NAME    [Toc]    [Back]
      ndd - network tuning

 SYNOPSIS    [Toc]    [Back]
      ndd -get network_device parameter

      ndd -set network_device parameter value

      ndd -h sup[ported]

      ndd -h unsup[ported]

      ndd -h [parameter]

      ndd -c

 DESCRIPTION    [Toc]    [Back]
      The ndd command allows the examination and modification of several
      tunable parameters that affect networking operation and behavior. It
      accepts arguments on the command line or may be run interactively. The
      -h option displays all the supported and unsupported tunable
      parameters that ndd provides. Valid network_device names are:
      /dev/arp, /dev/ip, /dev/rawip, /dev/tcp, and /dev/udp.  Set parameter
      to ? to get a list of parameters for a particular network_device.

      ndd -get            Get the value of the parameter for network_device
                          and print the value to standard output.  Returned
                          numbers are always displayed as decimal strings.

      ndd -set            Set parameter for network_device to value.

                          All times are specified in milliseconds, e.g.
                          240000 for 4 minutes.  Unless stated otherwise,
                          numbers are assumed to be in decimal. Use "0x"
                          prefix to specify hexadecimal values.

                          In general, all tunable parameters are global,
                          i.e., they affect all instances of the network
                          module. Some settings take effect immediately,
                          while others are used to initialize data for an
                          instance and will only affect newly opened
                          streams.

      ndd -h supported    Display all the supported tunable parameters. This
                          set of parameters are supported by HP and detailed
                          descriptions of these tunable parameters are
                          available through the -h parameter command.

      ndd -h unsupported  Display all the unsupported tunable parameters.
                          This set of parameters are not supported by HP and
                          modification of these tunable parameters are not



 Hewlett-Packard Company            - 1 -   HP-UX 11i Version 2: August 2003






 ndd(1M)                                                             ndd(1M)




                          suggested nor recommended. Setting any unsupported
                          tunable parameters on your system may result in
                          adverse effects to your networking operations.

      ndd -h              When parameter is specified, a detail description
                          of the parameter, along with its minimum, maximum,
                          and default value are displayed.  If no parameter
                          is specified, it displays all supported and
                          unsupported tunable parameters.

      ndd -c              Read input from the configuration file
                          /etc/rc.config.d/nddconf and set the tunable
                          parameters. A user may specify tunable parameters
                          in the nddconf configuration file, and these
                          parameters will be set automatically each time the
                          system boots.

 DIAGNOSTICS    [Toc]    [Back]
      When the command fails, an error message is printed to the standard
      error and the command terminates with an exit value of one.

 WARNINGS    [Toc]    [Back]
      Care must be used when setting parameters for a network_device.
      Setting a tunable parameter to an inappropriate value can result in
      adverse affects to your networking operations.

 EXAMPLES    [Toc]    [Back]
      To get help information on all supported tunable parameters:
           ndd -h supported

      To get a detail description of the tunable parameter, ip_forwarding:
           ndd -h ip_forwarding

      To get a list of all TCP related parameters:
           ndd -get /dev/tcp ?

      To get the current value of the tunable parameter, ip_forwarding:
           ndd -get /dev/ip ip_forwarding

      To set the value of the default TTL parameter for UDP to 128:

           ndd -set /dev/udp udp_def_ttl 128

 FILES    [Toc]    [Back]
      /etc/rc.config.d/nddconf                Contains tunable parameters
                                              that will be set automatically
                                              each time the system boots.

 AUTHOR    [Toc]    [Back]
      ndd was developed by HP.


 Hewlett-Packard Company            - 2 -   HP-UX 11i Version 2: August 2003