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6TUNNEL(1)		     General Commands Manual		      6TUNNEL(1)

NAME
     6tunnel - tunnelling for application that don't speak IPv6

SYNOPSIS
     6tunnel  [ -146dhfvV ] [ -u username ] [ -i password ] [ -I password ] [ -l
     local_host ] [ -L limit ] [ -p pid_file ] [ -m map_file  ]  local_port  re-
     mote_host [ remote_port ]

DESCRIPTION
     6tunnel  allows  you  to use services provided by IPv6 hosts with IPv4-only
     applications and vice-versa. It can bind to any of your IPv4  (default)  or
     IPv6 addresses and forward all data to IPv4 or IPv6 (default) host. For ex-
     ample

	    6tunnel -1 6668 irc6.net 6667

     will be enough to connect to IPv6 irc server with

	    irc foobar localhost:6668

     If you don't wish to run 6tunnel every time you want to show your :c001: or
     :dead:  IPv6  address on IRC, you can use -i parameter, which makes 6tunnel
     ask your client for specified password. Just run

	    6tunnel -i dupa.8 31337 irc6.net 6667

     and then type

	    irc foobar localhost:31337:dupa.8

     If your IRC server requires you to send password, specify it with -I  para-
     meter  -- after successful proxy authentication 6tunnel will send it to the
     server.

     6tunnel can also be used as a tunnel for all other combinations of IPv4 and
     IPv6 endpoints. If remote host doesn't have  any  IPv6  addresses,  6tunnel
     will  use	the  IPv4 one. In other cases, use -4 parameter which makes IPv4
     address the preferred one. For IPv6-to-any tunnels use -6 which makes 6tun-
     nel bind to IPv6 address.

OPTIONS
     -1     Exit after first connection.

     -4     Prefer IPv4 endpoint if the machine has both address types.

     -6     Listen on IPv6 address (IPv4 is default).

     -d     Don't detach.

     -f     Force tunneling even if remote host is not resolvable at the  execu-
	    tion time.

     -h     Print hex dump of every packet received or sent.

     -u username
	    Change UID and GID after bind().

     -i password
	    Act as an IRC proxy and require user to authenticate.

     -I password
	    If you are using 6tunnel as an IRC proxy and the IRC server requires
	    you to send password, place it right here.

     -l local_host
	    Listen on specified address (IPv4, or IPv6 if -6 used).

     -L limit
	    Limit simultaneous connections.

     -p pid_file
	    Write down pid to specified file.

     -s source_host
	    Connect to the remote host using specified source address.

     -m map_file
	    Binds  to  specified IPv6 addresses on basis of source IPv4 address.
	    The file contains one mapping per line with IPv4 source address  and
	    corresponding  IPv6  address.  Only listed hosts are allowed to con-
	    nect. If you want to allow any host,  add  mapping	for  default  or
	    0.0.0.0 address. Example:

	    192.168.0.2 3ffe:8010:18::1000:2
	    192.168.0.3 3ffe:8010:18::1000:3

     -v     Be verbose and don't detach.

     -V     Print version and exit.

NOTES
     Option  -H to disable all resolver hints has been removed since proper com-
     bination of -4 and -6 will yield  in  any	combination  of  IPv4  and  IPv6
     sources and destinations.

SIGNALS
     Sending SIGHUP forces map file reload.

THANKS
     #ipv6 crew, Lam.

BUGS
     Terrible  man page. Hex dump doesn't include IRC proxy authentication.  IRC
     proxy requires your client to send password first (don't worry ircii, EPIC,
     BitchX, mIRC and many more will work). No logging except debug output.

AUTHORS
     Wojtek   Kaniewski   (wojtekka@toxygen.net),   Dariusz    Jackowski    (as-
     cent@linux.pl),  Ramunas  Lukosevicus  (lukoramu@parok.lt),  Roland  Stigge
     (stigge@antcom.de)

SEE ALSO
     ssh(1)

				   2025-07-10			      6TUNNEL(1)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=6tunnel&sektion=1&manpath=FreeBSD+Ports+15.1.quarterly>

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