If we wish to run a server for website hosting or accessing CCTV cameras, available from any Internet location - and we don't have a static IP address but a dynamic one supplied by DHCP server (e.g. ADSL service) - we have to use DDNS (Dynamic Domain Name System).
DDNS server provides a database containing relations between domain names and numeric addresses, which may be updated on request, by the domain owner. Thanks to this feature, the server is available in the domain name regardless its current IP address.
We have to remember that when DHCP server changes the IP, it takes some time to detect this change by the client software or router. Then, after the notification has been sent to DDNS server, it takes another minute or so to send this piece of data to DNS server to update the database. As a result, our server will be periodically unavailable up to several minutes - every time the IP address has been changed.
DDNS server provides a database containing relations between domain names and numeric addresses, which may be updated on request, by the domain owner. Thanks to this feature, the server is available in the domain name regardless its current IP address.
We have to remember that when DHCP server changes the IP, it takes some time to detect this change by the client software or router. Then, after the notification has been sent to DDNS server, it takes another minute or so to send this piece of data to DNS server to update the database. As a result, our server will be periodically unavailable up to several minutes - every time the IP address has been changed.
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