Solution for dynamic DNS using nsupdate and cgi-bin script.
Instructions:
Create directory /var/www/cgi-bin/nsupdateCopy scripts into it.
Change domain in nsupdate.cgi and nsdelete.cgi
Drop nsupdate.conf in /etc/httpd/conf
Create passwords for names that are allowed to change it's dns A record:
$ cd /et/httpd$ htdigest -c user.passwd.nsupdate DNS <hostname>
On the machine that has a public dynamic IP or is on a private subnetbehind a NAT router with dynamic IP:
crontab -e
0,15,30,45 * * * * curl --digest --user <hostname>:<password> -s http://<YOURWEBSERVER>/nsupdate/nsupdate.cgi > /dev/null