NGCTL(8) FreeBSD System Manager's Manual NGCTL(8)


ngctlnetgraph control utility


ngctl [ -d][ -f filename][ -n nodename][ command ...]


The ngctl utility creates a new netgraph node of type socket which can be used to issue netgraph commands. If no -f flag is given, no command is supplied on the command line, and standard input is a tty, ngctl will enter interactive mode. Otherwise ngctl will execute the supplied command(s) and exit immediately.

Nodes can be created, removed, joined together, etc. ASCII formatted control messages can be sent to any node if that node supports binary/ASCII control message conversion.

In interactive mode, ngctl will display any control messages and data packets received by the socket node. In the case of control messages, the message arguments are displayed in ASCII form if the originating node supports conversion.

The options are as follows:

-f nodeinfo
Read commands from the named file. A single dash represents the standard input. Blank lines and lines starting with a “#” are ignored.
-n nodename
Assign nodename to the newly created netgraph node. The default name is ngctlXXX where XXX is the process ID number.
Increase the debugging verbosity level.


The currently supported commands in ngctl are:

config     get or set configuration of node at <path> 
connect    Connects hook <peerhook> of the node at <relpath> to <hook> 
debug      Get/set debugging verbosity level 
dot        Produce a GraphViz (.dot) of the entire netgraph. 
help       Show command summary or get more help on a specific command 
list       Show information about all nodes 
mkpeer     Create and connect a new node to the node at "path" 
msg        Send a netgraph control message to the node at "path" 
name       Assign name <name> to the node at <path> 
read       Read and execute commands from a file 
rmhook     Disconnect hook "hook" of the node at "path" 
show       Show information about the node at <path> 
shutdown   Shutdown the node at <path> 
status     Get human readable status information from the node at <path> 
types      Show information about all installed node types 
write      Send a data packet down the hook named by "hook". 
quit       Exit program

Some commands have aliases, e.g., “ls” is the same as “list”. The “help” command displays the available commands, their usage and aliases, and a brief description.


The ngctl utility exits 0 on success, and >0 if an error occurs.


The netgraph system was designed and first implemented at Whistle Communications, Inc. in a version of FreeBSD 2.2 customized for the Whistle InterJet.


Archie Cobbs <archie@whistle.com>
January 19, 1999 FreeBSD