dhid is the DHIS client daemon. After setting up with a DHIS provider, each machine may run a dhid daemon
(in background) in order to update its dynamic IP address within the server.
/etc/dhid.conf should be configured according to the provider's assigned parameters.
Once running, dhid sends echo request packets to the server and expects a reply. Once received, dhid
tries to authenticate at the server either in secure on insecure mode. From then on, and providing
authentication was successful, the client waits and replies to queries originated at the server. If the
server doesn't receive acknowledgments of these packets the host is marked offline. Likewise, if the
client doesn't receive queries for a period of time the offline stage is restored.
Therefore, the only thing a DHIS host needs is to run the dhid client. The server is able to determine
when the host is online and the server tables are updated automatically.