MIREDO(8)

💖 MIREDO 💖

section 8, System Manager's Manual — bestie, this is the Teredo IPv6 tunneling girlie for Unix, and she is ready to serve.

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✨ SYNOPSIS ✨

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

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🦋 DESCRIPTION 🦋

Miredo is a daemon program, okay, and what she does is provide a Teredo tunnel service that's compatible with the "Teredo: Tunneling IPv6 over UDP through NATs" Internet proposed standard, aka RFC 4380. She can do Teredo client duty or Teredo relay duty. Versatile queen 💅

Why do we even care? Because this is mostly useful for giving IPv6 connectivity to users stuck behind a NAT, and most NATs don't support IPv6 at all. And it gets worse — many NATs don't even support proto-41 forwarding, so you literally cannot set up a 6to4 or a point-to-point IPv6-over-IPv4 tunnel through them. The NAT said no. So we go around. 🧚

So like, the three roles, let me break it down:

• A Teredo relay is an IPv6 router which forwards IPv6 packets between the IPv6 Internet and Teredo clients by encapsulating those 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 — you knew that, iykyk), and it encapsulates its IPv6 traffic inside UDP over IPv4 packets.
• A Teredo server is a special Teredo relay which is required for Teredo clients to set up 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. 📬

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💅 OPTIONS 💅

• -c config_file or --config config_file — Specify an alternate configuration file for Miredo instead of the default, /etc/miredo/miredo.conf. Not feeling the default vibe? Swap it out. ✨
• -f or --foreground — Do not detach from the console. Run the program in the foreground. Main character energy, stays in the group chat. 🫶
• -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. So relay girlies can leave it empty, client girlies gotta pack their resolver files. 🎀
• -u username or --user username — Override the user that the program will run as. By default, it runs as nobody. Yes, literally 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). So if you're not in client mode, she's not listening, bestie. 💀

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🔒 SECURITY 🔒

Miredo requires root privileges to create her IPv6 tunneling network interface, and to set it up properly. Once her initialization is complete, she 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. Locked down, periodt. 🔐

However — and this is the part where you listen — 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 privileges separation. The process that handles data from the network is not privileged. So the network-facing part is just a little guy. 🥺

While that is not specific to nor dependent 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.

Not to be dramatic but that's kind of a big deal, so like, talk to your network admin before you get in trouble. 🙈

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🌸 SIGNALS 🌸

• SIGHUP — Force a reload of the daemon. Refresh her. ✨
• SIGINT, SIGTERM — Shutdown the daemon. Bye bestie 👋
• SIGUSR1, SIGUSR2 — Do nothing, might be used in future versions. They're just chilling. Doing nothing. Iconic, honestly. 💀

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🎀 FILES 🎀

• /etc/miredo/miredo.conf — The default configuration file. Her home base 💖
• /var/run/miredo.pid — The process-id file.

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👑 SEE ALSO 👑

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

Go read the whole friend group, they all ate. 🍓

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💜 AUTHOR 💜

Rémi Denis-Courmont <remi at remlab dot net>

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

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and that's the whole page, bestie 💖 this was the miredo manual page, section 8, dated February 2008. tysm for reading, no cap, you're gonna tunnel so good 🦋✨