Box: Mut@nt HD51 with OpenATV 6.0
DDNS account on Dynu.com
This how to is about setting automatic update of dynu.com DDNS on the box without any plugin using cron deamon and crontab.
It is required to know how to telnet to the box and execute some linux commands.

1. connect to your box using telnet client (i used PutTTY)
2. check if cron deamon is running:
Code:
ps -ef | grep cr[o]n
return will be location of cron deamon and crontab if cron deamon is runinng.
if there is no return then cron deamon not running or not installed and have to be installed or started
3. check if wget is installed
Code:
help wget
4. make direectory where you will store script and log file; for this example dir dynu in home dir (in this example root@mut@nthd51)
Code:
mkdir dynu
5. change directory
Code:
cd dynu
6. create scrip with vi editor
Code:
vi dynu.sh
7. edit script dynu.sh with vi editor (help here https : // www . cs . colostate . edu / helpdocs / vi . html):
this is how script should look:
Code:
wget -O ~/dynu/dynuLog "https://api.dynu.com/nic/update?hostname=example.dynu.com&username=someusername&password=somepassword&myip="
wget command help here: https : // www . gnu . org / software / wget / manual / wget . html
replace example.dynu.com with your dynu DDNS
replace someusername with your dynu username
replace somepasswordwith your dynu password; password should be md5 hash of your string password. you may create it here: https : // www . dynu . com / Networktools / MD5
myip parameter of wget URL left blank at the end of wget URL. this way dynu will detect your IP address and update DDNS record with it.
-O ~/dynu/dynuLog means that downloaded file with log will be stored in dynuLog file
8. change permission of the script:
Code:
chmod 700 dynu.sh
9. check if script is working
Code:
./dynu.sh
you should have response on the screen as well in the log file
10. create crontab schedule to execute dynu.sh script every 15 minutes (more info about cron & crontab here: http : // www . adminschoice . com / crontab-quick-reference )
Code:
crontab - e
11. using vi editor edit crontab, enter following text
Code:
*/15 * * * * ~/dynu/dynu.sh >/dev/null 2>&1
*/15 * * * * - means every 15 minutes script will be executed
~/dynu/dynu.sh - means dynu.sh script created above will be executed
>/dev/null 2>&1 - means no output will be sent by mail

That is it, your ddns should be checked every 15 minutes, cron deamon will run dynu.sh based on crontab schedule.