• DNS Docs from HE
• DNS listing from HE

In this example the Domain is test.dyn.julian-lemmerich.de and the password is MbSI4A0EsnxBcvWevVtF

curl -6 "https://test.dyn.julian-lemmerich.de:MbSI4A0EsnxBcvWevVtF@dyn.dns.he.net/nic/update?hostname=test.dyn.julian-lemmerich.de"
curl -4 "https://test.dyn.julian-lemmerich.de:MbSI4A0EsnxBcvWevVtF@dyn.dns.he.net/nic/update?hostname=test.dyn.julian-lemmerich.de"

This is an example of how to implement it with cron.

crontab -e

# Edit this file to introduce tasks to be run by cron.
#
 
MAILTO = ""
 
# DynDNS Update every 5 minutes
*/5 * * * * curl -6 "https://test.dyn.julian-lemmerich.de:MbSI4A0EsnxBcvWevVtF@dyn.dns.he.net/nic/update?hostname=test.dyn.julian-lemmerich.de"
*/5 * * * * curl -4 "https://test.dyn.julian-lemmerich.de:MbSI4A0EsnxBcvWevVtF@dyn.dns.he.net/nic/update?hostname=test.dyn.julian-lemmerich.de"