SYNOPSIS
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
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
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
When the command fails, an error message is printed to the standard error and
the command terminates with an exit value of one.
WARNINGS
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
To get help information on all supported tunable parameters:
To get a detail description of the tunable parameter,
ip_forwarding:
To get a list of all TCP related parameters:
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
- /etc/rc.config.d/nddconf
Contains tunable parameters that will be set automatically each time the system boots.
AUTHOR
ndd
was developed by HP.