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6tunnel(1) [debian man page]

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

6tunnel - tunnelling for application that don't speak IPv6 SYNOPSIS
6tunnel [ -146dhfv ] [ -u username ] [ -i password ] [ -I password ] [ -l local_host ] [ -L limit ] [ -p pid_file ] [ -m map_file ] local_port remote_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 example 6tunnel -1 6668 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 6667 and then type irc foobar localhost:31337:dupa.8 If your IRC server requires you to send password, specify it with -I parameter -- 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 preffered one. For IPv6-to-any tunnels use -6 which makes 6tunnel bind to IPv6 address. OPTIONS
-1 Exit after first connection. -4 Preffer 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 execution time. -h Print hex dump of every packet received or sent (hu-huh, Beavis, he said hex dump!) -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 connect. If you want to allow any host, add mapping for default or address. Example: 3ffe:8010:18::1000:2 3ffe:8010:18::1000:3 -v Be verbose and don't detach. 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 (, Dariusz Jackowski (, Ramunas Lukosevicus ( SEE ALSO
ssh(1) Aug 18, 2005 6TUNNEL(1)

Check Out this Related Man Page

FAITH(4)						   BSD Kernel Interfaces Manual 						  FAITH(4)

faith -- IPv6-to-IPv4 TCP relay capturing interface SYNOPSIS
device faith DESCRIPTION
The faith interface captures IPv6 TCP traffic, for implementing userland IPv6-to-IPv4 TCP relay like faithd(8). Each faith interface is created at runtime using interface cloning. This is most easily done with the ifconfig(8) create command or using the cloned_interfaces variable in rc.conf(5). Special action will be taken when IPv6 TCP traffic is seen on a router, and the routing table suggests to route it to the faith interface. In this case, the packet will be accepted by the router, regardless of the list of IPv6 interface addresses assigned to the router. The packet will be captured by an IPv6 TCP socket, if it has the IN6P_FAITH flag turned on and matching address/port pairs. As a result, faith will let you capture IPv6 TCP traffic to some specific destination addresses. Userland programs, such as faithd(8) can use this behavior to relay IPv6 TCP traffic to IPv4 TCP traffic. The program can accept some specific IPv6 TCP traffic, perform getsockname(2) to get the IPv6 destination address specified by the client, and perform application-specific address mapping to relay IPv6 TCP to IPv4 TCP. The IN6P_FAITH flag on a IPv6 TCP socket can be set by using setsockopt(2), with level IPPROTO_IPV6 and optname IPv6_FAITH. To handle error reports by ICMPv6, some ICMPv6 packets routed to an faith interface will be delivered to IPv6 TCP, as well. To understand how faith can be used, take a look at the source code of faithd(8). As the faith interface implements potentially dangerous operations, great care must be taken when configuring it. To avoid possible misuse, the sysctl(8) variable net.inet6.ip6.keepfaith must be set to 1 prior to using the interface. When net.inet6.ip6.keepfaith is 0, no packets will be captured by the faith interface. The faith interface is intended to be used on routers, not on hosts. SEE ALSO
inet(4), inet6(4), faithd(8) Jun-ichiro itojun Hagino and Kazu Yamamoto, An IPv6-to-IPv4 transport relay translator, RFC3142. HISTORY
The FAITH IPv6-to-IPv4 TCP relay translator first appeared in the WIDE hydrangea IPv6 stack. BSD
April 10, 1999 BSD

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