The quick way

Try it out within your own LAN! Follow these simple steps:

  • On your server, run:
    ./iodined -fP test test.asdf 

(If you already use the network, use another internal net like

  • On the client, run:
    ./iodine -fP test test.asdf 

(Replace with the server's ip address)

  • Now the client has the tunnel ip and the server has
  • Try pinging each other through the tunnel
  • Done! :)

Full setup

Server side:

To use this tunnel, you need control over a real domain (like, and a server with a static public IP number that does not yet run a DNS server. Then, delegate a subdomain (say, to the server. If you use BIND for the domain, add these lines to the zone file:

tunnel1host     IN      A
tunnel1         IN      NS

If you dont have a domain, it seems you can get a free subdomain with DNS control capable of NS records at

If you already have an A record (or a DynDNS name) to your server, you can use a CNAME to it instead of the A record above. Now any DNS querys for domains ending with will be sent to your server. Start iodined on the server. The first argument is the tunnel IP address (like and the second is the assigned domain (in this case The -f argument will keep iodined running in the foreground, which helps when testing. iodined will start a virtual interface, and also start listening for DNS queries on UDP port 53. Either enter a password on the commandline (-P pass) or after the server has started. 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 local relaying DNS server and the second is the domain used ( If DNS queries are allowed to any computer, you can use the tunnel endpoint (example: or as the first argument. The tunnel interface will get an IP close to the servers (in this case and a suitable MTU. Enter the same password as on the server either by argument or after the client has started. Now you should be able to ping the other end of the tunnel from either side.


The normal case is to route all traffic through the DNS tunnel. To do this, first add a route to the nameserver you use with the default gateway as gateway. Then replace the default gateway with the servers IP address within the DNS tunnel, and configure the server to do NAT.

Some scripts to configure the client can be found at the TipsAndTricks page.


Try the automatic tunnel tester at

Do not worry that you can not ping the tunnel domain. You can only ping domains that point to hosts (via A or CNAME records), so this is normal.

The most common error is that the domain is not correctly configured, or that there is a firewall blocking the traffic. Send NS requests for subdomains of your tunnel domain to test that it works.

dig -t NS

if is the domain used with iodined. Also add -DD to iodined arguments to see if any traffic arrives and is answered. When NS requests work, iodine should also work. You can also use network sniffers like tcpdump/tshark/wireshark to see if the traffic arrives.

To see what the DNS server has stored, first locate the server for your domain:

$ dig -t NS
; <<>> DiG 9.4.3-P3 <<>> -t NS
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 51859
;; flags: qr rd ra; QUERY: 1, ANSWER: 4, AUTHORITY: 0, ADDITIONAL: 4

;       IN      NS

;; ANSWER SECTION: 86367  IN      NS 86367  IN      NS 86367  IN      NS 86367  IN      NS

Here we see is handled by Use dig to ask it about the tunnel domain:

$ dig -t NS
; <<>> DiG 9.4.3-P3 <<>> -t NS
; (1 server found)
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 28284
;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0
;; WARNING: recursion requested but not available

; IN    NS


The right part of the single NS row here should be pointing to your server. You might also get an additional section, showing that host:

;; ADDITIONAL SECTION:          3600    IN      A

Always use the latest version and ask for help in the IRC channel if you have any more problems.

Other guides

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