diff --git a/README b/README index bd8c88e..043fa58 100644 --- a/README +++ b/README @@ -14,8 +14,8 @@ HOW TO USE: Server side: To use this tunnel, you need control over a real domain (like mytunnel.com), -and another computer with a static public IP number that does not yet run a DNS -server. Then, delegate a subdomain (say, tunnel1.mytunnel.com) to the computer. +and a server with a static public IP number that does not yet run a DNS +server. Then, delegate a subdomain (say, tunnel1.mytunnel.com) to the server. If you use BIND for the domain, add these lines to the zone file: tunnel1host IN A 10.15.213.99 @@ -31,15 +31,37 @@ foreground, which helps when testing. iodined will start a virtual interface, and also start listening for DNS queries on UDP port 53. Now everything is ready for the client. -Client side: -All the setup is done, just start iodine. It also takes two arguments, the -first is the server (10.15.213.99 or tunnel1host.mytunnel.com) and the second -is the domain used (tunnel1.mytunnnel.com). The tunnel interface will get an IP -close to the servers (in this case 192.168.99.2) and a suitable MTU. Now you -should be able to ping the other end of the tunnel from each side. +Client side: +All the setup is done, just start iodine. It also takes two +arguments, the first is the local relaying DNS server and the second is the +domain used (tunnel1.mytunnnel.com). If DNS queries are allowed to any +computer, you can use the tunnel endpoint (example: 10.15.213.99 or +tunnel1host.mytunnel.com) as the first argument. The tunnel interface will get +an IP close to the servers (in this case 192.168.99.2) and a suitable MTU. Now +you should be able to ping the other end of the tunnel from either side. -INFO: +MISC. INFO: + +Note that you can have only one client per server at the same time. This is +because of the fragmentation of big packets going upstream, and will be fixed +in future versions. + +Try experimenting with the MTU size (-m option) to get maximum bandwidth. It is +set to 1024 by default, which seems to work with most DNS servers. If you have +problems, try setting it to below 512. + +If you have problems, try inspecting the traffic with network monitoring tools +and make sure that the relaying DNS server has not cached the response. A +cached error message could mean that you started the client before the server. + +The upstream data is sent gzipped encoded in hexadecimal. DNS protocol allows +one query per packet, and one query can be max 256 chars. Each domain name part +can be max 63 chars. So your domain name and subdomain should be as short as +possible to allow maximum throughput. + + +PORTABILITY: iodine has been tested on Linux (x86 and SPARC64) and OpenBSD (x86). It should work on other unix-like systems as well that has TUN/TAP tunneling support. Let @@ -49,21 +71,21 @@ us know if you get it to run on other platforms. THE NAME: The name iodine was chosen since it starts with IOD (IP Over DNS) and since -iodine has atomic number 53, just like the DNS port. +iodine has atomic number 53, which happens to be the DNS port number. AUTHORS & LICENSE: Copyright (c) 2006 Bjorn Andersson , Erik Ekman -Permission to use, copy, modify, and distribute this software for any -purpose with or without fee is hereby granted, provided that the above -copyright notice and this permission notice appear in all copies. +Permission to use, copy, modify, and distribute this software for any purpose +with or without fee is hereby granted, provided that the above copyright notice +and this permission notice appear in all copies. -THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES -WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF -MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR -ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES -WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN -ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF -OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. +THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH +REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND +FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, +INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM +LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR +OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR +PERFORMANCE OF THIS SOFTWARE.