NAME

       miredo - Teredo IPv6 tunneling for Unix

SYNOPSIS

       miredo [-c config_file] [-f] [-u user] [ -t chrootdir] [server_name]

DESCRIPTON

       Miredo  is a daemon program providing a Teredo tunnel service compatible with the "Teredo:
       Tunneling IPv6 over UDP through NATs"  Internet  proposed  standard  (RFC  4380).  It  can
       provide either Teredo client or Teredo relay functionality.

       This  is  mostly useful to provide IPv6 connectivity to users behind NAT, most of which do
       not support IPv6 at all. Many NATs do not even support proto-41 forwarding, so it  is  not
       possible to set up a 6to4 or point-to-point IPv6-over-IPv4 tunnel through them.

       A Teredo relay is an IPv6 router which forwards IPv6 packets between the IPv6 Internet and
       Teredo clients by encapsulating these IPv6 packets over UDP/IPv4.

       A Teredo client is an IPv6-enabled host which  is  located  behind  an  IPv4-only  Network
       Address  Translator  (a.k.a.  NAT), and encapsulates its IPv6 traffic inside UDP over IPv4
       packets.

       A Teredo server is a special Teredo relay which is required for Teredo  clients  to  setup
       their  IPv6  connectivity  through  Teredo.  A  Teredo  server  must have to global static
       subsequent IPv4 addresses. It receives packets from Teredo clients and  Teredo  relays  on
       UDP port 3544.

OPTIONS

       -c config_file or --config config_file
              Specify  an  alternate  configuration  file  for  Miredo  instead  of  the default,
              /etc/miredo/miredo.conf.

       -f or --foreground
              Do not detach from the console. Run the program in the foreground.

       -h or --help
              Display some help and exit.

       -t or --chrootdir
              Specify a directory to use as a root after initialization is completed.  When  used
              as  a  Teredo  client,  the  hostname resolver library files must be present in the
              chroot. The directory can safely be left empty for a Teredo relay.

       -u username or --user username
              Override the user that the program will run as. By default, it runs as nobody.

       -V or --version
              Display program version and license and exit.

       server_name
              This optional command argument specifies a Teredo server to use. It  will  override
              any  ServerAddress  directive  found  in  the  configuration file. It is ignored if
              RelayType is not set to "client" (see miredo.conf).

SECURITY

       Miredo requires root privileges to create its IPv6 tunneling network interface, and to set
       it  up properly. Once its initialization is complete, it will setgid, chroot into an empty
       directory and ultimately setuid (see option -u), so as to decrease the  system's  exposure
       to  potential  security  issues. However, if Miredo runs as a Teredo client, it needs root
       privileges when running, in order to  change  the  tunneling  network  interface  settings
       automatically.   To   prevent  possible  root  compromise,  Miredo  implements  priveleges
       separation. The process that handles data from the network is not privileged.

       While that is not specific to nor dependant on Miredo, it  should  be  noted  that  Teredo
       connectivity  allows  anyone  behind  a  NAT to obtain global public IPv6 connectivity. It
       might break some corporate policy.  If  that  is  an  issue,  outgoing  UDP  packets  with
       destination port 3544 should be blocked at the perimeter firewall.

SIGNALS

       SIGHUP Force a reload of the daemon.

       SIGINT, SIGTERM Shutdown the daemon.

       SIGUSR1, SIGUSR2 Do nothing, might be used in future versions.

FILES

       /etc/miredo/miredo.conf
              The default configuration file.

       /var/run/miredo.pid
              The process-id file.

SEE ALSO

       miredo.conf(5), miredo-server(8), ipv6(7), route(8), ip(8)

AUTHOR

       Rémi Denis-Courmont <remi at remlab dot net>

       http://www.remlab.net/miredo/