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ANYTUN(8)   ANYTUN(8)

NAME

anytun - anycast tunneling daemon

SYNOPSIS

anytun


  [ -h|--help ]


  [ -D|--nodaemonize ]


  [ -u|--username <username> ]


  [ -g|--groupname <groupname> ]


  [ -C|--chroot <path> ]


  [ -P|--write-pid <filename> ]


  [ -L|--log <target>:<level>[,<param1>[,<param2>[..]]] ]


  [ -U|--debug ]


  [ -i|--interface <ip-address> ]


  [ -p|--port <port> ]


  [ -r|--remote-host <hostname|ip> ]


  [ -o|--remote-port <port> ]


  [ -4|--ipv4-only ]


  [ -6|--ipv6-only ]


  [ -I|--sync-interface <ip-address> ]


  [ -S|--sync-port port> ]


  [ -M|--sync-hosts <hostname|ip>[:<port>][,<hostname|ip>[:<port>][...]] ]


  [ -X|--control-host <hostname|ip>[:<port>]


  [ -d|--dev <name> ]


  [ -t|--type <tun|tap> ]


  [ -n|--ifconfig <local>/<prefix> ]


  [ -x|--post-up-script <script> ]


  [ -R|--route <net>/<prefix length> ]


  [ -m|--mux <mux-id> ]


  [ -s|--sender-id <sender id> ]


  [ -w|--window-size <window size> ]


  [ -k|--kd-prf <kd-prf type> ]


  [ -e|--role <role> ]


  [ -E|--passphrase <pass phrase> ]


  [ -K|--key <master key> ]


  [ -A|--salt <master salt> ]


  [ -c|--cipher <cipher type> ]


  [ -a|--auth-algo <algo type> ]


  [ -b|--auth-tag-length <length> ]

DESCRIPTION

Anytun is an implementation of the Secure Anycast Tunneling Protocol (SATP). It provides a complete VPN solution similar to OpenVPN or IPsec in tunnel mode. The main difference is that anycast allows a setup of tunnels between an arbitrary combination of anycast, unicast and multicast hosts.

OPTIONS

Anytun has been designed as a peer to peer application, so there is no difference between client and server. The following options can be passed to the daemon:

-D, --nodaemonize

This option instructs Anytun to run in foreground instead of becoming a daemon which is the default.

-u, --username <username>

run as this user. If no group is specified (-g) the default group of the user is used. The default is to not drop privileges.

-g, --groupname <groupname>

run as this group. If no username is specified (-u) this gets ignored. The default is to not drop privileges.

-C, --chroot <path>

Instruct Anytun to run in a chroot jail. The default is to not run in chroot.

-P, --write-pid <filename>

Instruct Anytun to write it’s pid to this file. The default is to not create a pid file.

-L, --log <target>:<level>[,<param1>[,<param2>[..]]]

add log target to logging system. This can be invoked several times in order to log to different targets at the same time. Every target hast its own log level which is a number between 0 and 5. Where 0 means disabling log and 5 means debug messages are enabled.

The file target can be used more the once with different levels. If no target is provided at the command line a single target with the config syslog:3,anytun,daemon is added.

The following targets are supported:

syslog

log to syslog daemon, parameters <level>[,<logname>[,<facility>]]

file

log to file, parameters <level>[,<path>]

stdout

log to standard output, parameters <level>

stderr

log to standard error, parameters <level>

-U, --debug

This option instructs Anytun to run in debug mode. It implicits -D (don’t daemonize) and adds a log target with the configuration stdout:5 (logging with maximum level). In future releases there might be additional output when this option is supplied.

-i, --interface <ip address>

This IP address is used as the sender address for outgoing packets. In case of anycast tunnel endpoints, the anycast IP has to be used. In case of unicast endpoints, the address is usually derived correctly from the routing table. The default is to not use a special interface and just bind on all interfaces.

-p, --port <port>

The local UDP port that is used to send and receive the payload data. The two tunnel endpoints can use different ports. If a tunnel endpoint consists of multiple anycast hosts, all hosts have to use the same port. default: 4444

-r, --remote-host <hostname|ip>

This option can be used to specify the remote tunnel endpoint. In case of anycast tunnel endpoints, the anycast IP address has to be used. If you do not specify an address, it is automatically determined after receiving the first data packet.

-o, --remote-port <port>

The UDP port used for payload data by the remote host (specified with -p on the remote host). If you do not specify a port, it is automatically determined after receiving the first data packet.

-4, --ipv4-only

Resolv to IPv4 addresses only. The default is to resolv both IPv4 and IPv6 addresses.

-6, --ipv6-only

Resolv to IPv6 addresses only. The default is to resolv both IPv4 and IPv6 addresses.

-I, --sync-interface <ip-address>

local unicast(sync) ip address to bind to

This option is only needed for tunnel endpoints consisting of multiple anycast hosts. The unicast IP address of the anycast host can be used here. This is needed for communication with the other anycast hosts. The default is to not use a special interface and just bind on all interfaces. However this is only the case if synchronisation is active see --sync-port.

-S, --sync-port <port>

local unicast(sync) port to bind to

This option is only needed for tunnel endpoints consisting of multiple anycast hosts. This port is used by anycast hosts to synchronize information about tunnel endpoints. No payload data is transmitted via this port. By default the synchronisation is disabled an therefore the port is kept empty.

It is possible to obtain a list of active connections by telnetting into this port. This port is read-only and unprotected by default. It is advised to protect this port using firewall rules and, eventually, IPsec.

-M, --sync-hosts <hostname|ip>[:<port>],[<hostname|ip>[:<port>][...]]

remote hosts to sync with

This option is only needed for tunnel endpoints consisting of multiple anycast hosts. Here, one has to specify all unicast IP addresses of all other anycast hosts that comprise the anycast tunnel endpoint. By default synchronisation is disabled and therefore this is empty. Mind that the port can be omitted in which case port 2323 is used. If you want to specify an ipv6 address and a port you have to use [ and ] to separate the address from the port, eg.: [::1]:1234. If you want to use the default port [ and ] can be omitted.

-X, --control-host <hostname|ip>[:<port>]

fetch the config from this host. The default is not to use a control host and therefore this is empty. Mind that the port can be omitted in which case port 2323 is used. If you want to specify an ipv6 address and a port you have to use [ and ] to separate the address from the port, eg.: [::1]:1234. If you want to use the default port [ and ] can be omitted.

-d, --dev <name>

device name

By default, tapN is used for Ethernet tunnel interfaces, and tunN for IP tunnels, respectively. This option can be used to manually override these defaults.

-t, --type <tun|tap>

device type

Type of the tunnels to create. Use tap for Ethernet tunnels, tun for IP tunnels.

-n, --ifconfig <local>/<prefix>

The local IP address and prefix length. The remote tunnel endpoint has to use a different IP address in the same subnet.

<local>

the local IP address for the tun/tap device

<prefix>

the prefix length of the network

-x, --post-up-script <script>

This option instructs Anytun to run this script after the interface is created. By default no script will be executed.

-R, --route <net>/<prefix length>

add a route to connection. This can be invoked several times.

-m, --mux <mux-id>

the multiplex id to use. default: 0

-s, --sender-id <sender id>

Each anycast tunnel endpoint needs a unique sender id (1, 2, 3, ...). It is needed to distinguish the senders in case of replay attacks. This option can be ignored on unicast endpoints. default: 0

-w, --window-size <window size>

seqence window size

Sometimes, packets arrive out of order on the receiver side. This option defines the size of a list of received packets' sequence numbers. If, according to this list, a received packet has been previously received or has been transmitted in the past, and is therefore not in the list anymore, this is interpreted as a replay attack and the packet is dropped. A value of 0 deactivates this list and, as a consequence, the replay protection employed by filtering packets according to their secuence number. By default the sequence window is disabled and therefore a window size of 0 is used.

-k, --kd—prf <kd-prf type>

key derivation pseudo random function

The pseudo random function which is used for calculating the session keys and session salt.

Possible values:

null

no random function, keys and salt are set to 0..00

aes-ctr

AES in counter mode with 128 Bits, default value

aes-ctr-128

AES in counter mode with 128 Bits

aes-ctr-192

AES in counter mode with 192 Bits

aes-ctr-256

AES in counter mode with 256 Bits

-e, --role <role>

SATP uses different session keys for inbound and outbound traffic. The role parameter is used to determine which keys to use for outbound or inbound packets. On both sides of a vpn connection different roles have to be used. Possible values are left and right. You may also use alice or server as a replacement for left and bob or client as a replacement for right. By default left is used.

-E, --passphrase <passphrase>

This passphrase is used to generate the master key and master salt. For the master key the last n bits of the SHA256 digest of the passphrase (where n is the length of the master key in bits) is used. The master salt gets generated with the SHA1 digest. You may force a specific key and or salt by using --key and --salt.

-K, --key <master key>

master key to use for key derivation

Master key in hexadecimal notation, e.g. 01a2b3c4d5e6f708a9b0cadbecfd0fa1, with a mandatory length of 32, 48 or 64 characters (128, 192 or 256 bits).

-A, --salt <master salt>

master salt to use for key derivation

Master salt in hexadecimal notation, e.g. 01a2b3c4d5e6f708a9b0cadbecfd, with a mandatory length of 28 characters (14 bytes).

-c, --cipher <cipher type>

payload encryption algorithm

Encryption algorithm used for encrypting the payload

Possible values:

null

no encryption

aes-ctr

AES in counter mode with 128 Bits, default value

aes-ctr-128

AES in counter mode with 128 Bits

aes-ctr-192

AES in counter mode with 192 Bits

aes-ctr-256

AES in counter mode with 256 Bits

-a, --auth-algo <algo type>

message authentication algorithm

This option sets the message authentication algorithm.

If HMAC-SHA1 is used, the packet length is increased. The additional bytes contain the authentication data. see --auth-tag-length for more info.

Possible values:

null

no message authentication

sha1

HMAC-SHA1, default value

-b, --auth-tag-length <length>

The number of bytes to use for the auth tag. This value defaults to 10 bytes unless the null auth algo is used in which case it defaults to 0.

EXAMPLES

P2P Setup between two unicast enpoints:

Host A:

anytun -r hostb.example.com -t tun -n 192.168.123.1/30 -c aes-ctr-256 -k aes-ctr-256 \ -E have_a_very_safe_and_productive_day -e left

Host B:

anytun -r hosta.example.com -t tun -n 192.168.123.2/30 -c aes-ctr-256 -k aes-ctr-256 \ -E have_a_very_safe_and_productive_day -e right

One unicast and one anycast tunnel endpoint:

Unicast tunnel endpoint:

anytun -r anycast.anytun.org -d anytun0 -t tun -n 192.0.2.2/30 -a null -c null -w 0 -e client

Anycast tunnel endpoints:

On the host with unicast hostname unicast1.anycast.anytun.org and anycast hostname anycast.anytun.org:

# anytun -i anycast.anytun.org -d anytun0 -t tun -n 192.0.2.1/30 -a null -c null -w 0 -e server \


         -S 2342 -M unicast2.anycast.anytun.org:2342,unicast3.anycast.anytun.org:2342

On the host with unicast hostname unicast2.anycast.anytun.org and anycast hostname anycast.anytun.org:

# anytun -i anycast.anytun.org -d anytun0 -t tun -n 192.0.2.1/30 -a null -c null -w 0 -e server \


         -S 2342 -M unicast1.anycast.anytun.org:2342,unicast3.anycast.anytun.org:2342

On the host with unicast hostname unicast3.anycast.anytun.org and anycast hostname anycast.anytun.org:

# anytun -i anycast.anytun.org -d anytun0 -t tun -n 192.0.2.1/30 -a null -c null -w 0 -e server \


         -S 2342 -M unicast1.anycast.anytun.org:2342,unicast2.anycast.anytun.org:2342

For more sophisticated examples (like multiple unicast endpoints to one anycast tunnel endpoint) please consult the man page of anytun-config(8).

BUGS

Most likely there are some bugs in Anytun. If you find a bug, please let the developers know at satp@anytun.org. Of course, patches are preferred.

SEE ALSO

anytun-config(8), anytun-controld(8), anytun-showtables(8)

AUTHORS

Othmar Gsenger <otti@anytun.org> Erwin Nindl <nine@anytun.org> Christian Pointner <equinox@anytun.org>

RESOURCES

Main web site: http://www.anytun.org/

COPYING

Copyright (C) 2007-2014 Markus Grüneis, Othmar Gsenger, Erwin Nindl and Christian Pointner. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or any later version.

01/06/2020