System Administration Guide: IP Services

in.ndpd Daemon, for Neighbor Discovery

Thein.ndpd daemon implements the IPv6 Neighbor Discovery protocol and router discovery. The daemon also implements address autoconfiguration for IPv6. The following shows the supported options of in.ndpd.


Turns on debugging.


Turns on debugging for specific events.


Specifies a file to read configuration data from, instead of the default /etc/inet/ndpd.conf file.


Prints related information for each interface.


Does not loop back router advertisements.


Ignores received packets.


Specifies verbose mode, reporting various types of diagnostic messages.


Turns on packet tracing.

The in.ndpd daemon is controlled by parameters that are set in the /etc/inet/ndpd.conf configuration file and any applicable parameters in the /var/inet/ndpd_state.interface startup file.

When the /etc/inet/ndpd.conf file exists, the file is parsed and used to configure a node as a router. Table 11–2 lists the valid keywords that might appear in this file. When a host is booted, routers might not be immediately available. Advertised packets by the router might be dropped. Also, advertised packets might not reach the host.

The /var/inet/ndpd_state.interface file is a state file. This file is updated periodically by each node. When the node fails and is restarted, the node can configure its interfaces in the absence of routers. This file contains the interface address, the last time that the file was updated, and how long the file is valid. This file also contains other parameters that are “learned” from previous router advertisements.

Note –

You do not need to alter the contents of state files. The in.ndpd daemon automatically maintains state files.

See the in.ndpd(1M) man page and the ndpd.conf(4) man page for lists of configuration variables and allowable values.