NDD(1M) Maintenance Commands NDD(1M)
ndd - get and set driver configuration parameters
] driver parameter
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
the value associated with the specified parameter
, and prints it. If the -set
option is given, ndd
, 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 special read-only parameter
'' which can be used to list the parameters supported
by the driver.
Example 1: Getting Parameters Supported By The TCP Driver
To see which parameters are supported by the TCP driver, use the
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
the dual stack IP driver to zero. This disables IPv4 packet forwarding.
example% ndd -set /dev/ip ip_forwarding 0
Similarly, in order to disable IPv6 packet forwarding, the value of
example% ndd -set /dev/ip ip6_forwarding 0
SEE ALSO nca(1)
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
command that ndd
uses to communicate with drivers is likely
to change in a future release. User programs should avoid making
dependencies on it.
The use of ndd
to administer Layer 2 (Data Link layer) drivers is
strongly discouraged as this capability is to be obsoleted in a future
release, replaced by dladm(1M)
. Please refer to the driver-specific man
page in section 7D of the SunOS man pages.
The meanings of many ndd
parameters make sense only if you understand how
the driver is implemented.
If a TCP driver sends a report that is truncated, it could be because
that driver uses ndd
for transporting the report. ndd
imposes a 64K
limit on such reports.
March 13, 2009 NDD(1M)