This can be usable in different situations where internet access is firewalled, but DNS queries are allowed.

iodine runs on Mac OS X, Linux, FreeBSD, NetBSD and OpenBSD and needs a TUN/TAP device.

The bandwidth is assymetrical with limited upstream and up to 1 Mbit/s downstream.

The name iodine was chosen since it starts with IOD (IP Over DNS) and since
iodine has atomic number 53, which happens to be the DNS port number.

NOTE: iodine is licensed and distributed under the terms of the ISC license.

Here are some key features of "iodine":

· iodine uses the NULL type that allows the downstream data to be sent without encoding. Each DNS reply can contain nearly a kilobyte of payload data.
· iodine runs on many different UNIX-like systems. Tunnels can be set up between two hosts no matter their endianness or operating system.
· iodine uses challenge-response login secured by MD5 hash. It also filters out any packets not coming from the IP used when logging in.
· iodine handles setting IP number on interfaces automatically, and up to 8 users can share one server at the same time.

What's New in This Release: [ read full changelog ]

· Fixed tunnel not working on Windows.
· Any device name is now supported on Windows, fixes #47.
· Multiple installed TAP32 interfaces are now supported, fixes #46.
· Return nonzero if tunnel fails to open, fixes #62.
· Support for setting a SELinux context, based on patch by Sebastien Raveau. Sample context file in doc/iodine.te
· Allow listen port and DNS forward port to be the same if listen IP does not include localhost.
· The client will now exit if configuring IP or MTU fails.
· The starting cache miss value is randomized at startup, fixes #65.
· Raw UDP mode added. If the iodined server is reachable directly, packets can be sent to it without DNS encoding. Fixes #36.
· Do not overwrite users CC/CFLAGS/LDFLAGS, only add to them.
· Added -F option to write pidfile, based on patch from misc at mandriva.org. Fixes #70.
· Allow password to be set via environment variable, fixes #77. Based on patch by logix.
· Client now prints server tunnel IP, fixes #78. Patch by logix.
· Fix build error on Mac OS X 10.6, pa...