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DTCPC(8)		  BSD System Manager's Manual		      DTCPC(8)

     dtcpc -- Dynamic Tunnel Configuration Protocol client

     dtcpc [-a]	[-A address] [-b udp-port] [-c]	[-d] [-D] [-f file] [-i	if]
	   [-l]	[-m mtu] [-n] [-o] [-p port] [-P prefix-delegation]
	   [-r routecommand] [-R destination] [-t tuntype] [-u user] [-U]

     dtcpc implements Dynamic Tunnel Configuration Protocol (DTCP for short)
     proposed by Trumpet.  dtcpc will first ask	the DTCP password to the user.
     Then, the program will try	to connect DTCP	server on server, to IPv4 TCP
     port 20200	(or port specified by port), login as DTCP client, and main-
     tain IPv6 over IPv4 tunnel	connection.

     The spec defines several kind of tunnel requests.	dtcpc will request
     tunnel typed tuntype to the DTCP server.  The default value for tuntype
     is	"tunnelonly".  For tunnel types, please	refer to dtcps(8).

     By	default, dtcpc dynamically creates gif as tunnelling device on such
     platform as interface cloning is available.  You can disable use of in-
     terface cloning by	using -c.  When	-o is specified, dtcpc creates an in-
     terface dynamically but don't destroy it at exit.	On the platform	where
     interface cloning is not available, dtcpc will use	gif0 as	tunnelling de-
     vice.  This can be	altered	by using -i.

     If	-U is specified, an IPv6 over an UDP/IPv4 tunnel is created instead of
     generic tunnel.  An UDP port is specified by -b, and its default is
     "4028".  An IPv6 over an UDP/IPv4 tunnel requires Netgraph.  (Experimen-

     -r	specifies how the default route	is configured.	If "static" is speci-
     fied as routecommand, dtcpc uses the route(8) command to install the de-
     fault route towards the corresponding tunnel interface.  This is the de-
     fault behavior.  If "solicit" is specified, dtcpc will call the rtsol(8)
     command to	send router solicitation messages toward the other end of the

     By	default, when routecommand is "static",	the default route is config-
     ured.  But, in some situation, you	may want to install the	specific
     routes instead of the default route towards the corresponding tunnel in-
     terface.  You can specify the destination with -R destination.  The
     destination is an acceptable form by route(8), like as "3ffe:505:2::
     -prefixlen	48".  If you are running recent	FreeBSD, it can	be simplifed
     by	"3ffe:505:2::/48".  The	destination may	be comma separated list.

     -u	is needed when DTCP user account is different from the login name on
     the host.

     When -A address is	specified, address is added to the corresponding tun-
     nel interface.  The address is a acceptable form by ifconfig(8), like as
     "3ffe:505:2:ffff::1 -prefixlen 128".  It may help some situation.	The
     address may be comma separated list.

     -n	may save the user lives	behind NAT that	maps private IPv4 address to
     global IPv4 address.

     dtcpc can be configured to	do prefix-delegation.  When -P
     prefix-delegation is specified, dtcpc initialize the LAN interfaces.  The
     format of prefix-delegation is a comma separated list of the interface,
     SLA-id, host-id and prefixlen.  And the interface,	SLA-id,	host-id	and
     prefixlen should be written as a slant separated list such	as
     "fxp0/1/0:0:0:1".	If you omit host-id, EUI-64 address is assumed to be
     used.  If you omit	prefixlen, 64 is assumed.

     When prefix-delegation is enabled and rtadvd(8) is	not running, dtcpc in-
     vokes rtadvd(8) appropriately.  You can disable this behvior by specify-
     ing -a.

     When -D is	specified, dtcpc becomes daemon.

     By	default, when connection to the	server is closed, dtcpc	will exit.  -l
     is	specified, dtcpc doesn't exit on connection close, and continuously
     tries to re-connect.

     If	dtcpc is invoked as daemon, the	process	ID of the dtcpc	are held in
     /var/run/	by default.  You may want to specify -f	file to	change
     the file name.

     When -m mtu is specified, set the MTU of the tunnel to mtu.  The default
     is	"1280".

     -d	puts dtcpc to debug mode.

     Upon receipt of signal SIGHUP, dtcpc will try to reconnect	to the DTCP

     dtcpc will	exit with positive value on errors.

	       You can specify your password to	connect	to DTCP	server in this
	       file.  If your password is found	in this	file, dtcpc does not
	       ask for your password.  The format is a colon-separated list of
	       the server name,	the user name and the password.
	       Contains	the process ID of the dtcpc listening for connections.
	       The content of this file	is not sensitive; it can be world-
	       readable.  This file name may be	changed	by -f option.

     gif(4), dtcps(8), gifconfig(8), ifconfig(8), route(8), rtadvd(8)

     The dtcpc command first appeared in WIDE/KAME IPv6	protocol stack kit.

     "network" tunnel type and other useful facilities were added by Hajimu
     UMEMOTO <>.

     dtcpc will	not work if you	are behind a NAT box (This is a	protocol
     feature, not a bug).  -n may help you on such case.  But, it is still de-
     pend on the behavior of your NAT box.

     dtcpc was written in Ruby.	:-)

BSD				  Jan 6, 2006				   BSD


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