Dynamic DNS is a technology that allows information on the DNS server to be updated in real time and, if desired, in automatic mode. It is used to assign a permanent domain name to a device (computer, network drive) with a dynamic IP address. This can be an IP address obtained via DHCP or IPCP in PPP connections, for example, with remote access via a modem. Other machines on the Internet can connect to this machine by domain name and not even know that the IP address has changed.
The lifetime (TTL) (see RFC 1034) for dynamic recording is made very short (no more than two to three minutes), otherwise other DNS servers will put it in their cache, and when it changes, their clients will receive outdated information for a long time.
Dynamic DNS is also often used in local networks, where clients obtain an IP address via DHCP, and then register their names in a local DNS server.
The protocol for updating DNS is described in RFC 2136 and is implemented, for example, by the nsupdate utility. For secure client authentication, TSIG technology (RFC 2845), which uses a pre-known key, can be used. The disadvantage of this technology is that the key must be installed on each client and server.
For updating, special client programs are usually used, which can also use HTTP GET requests to update data.
Hosting and other companies that store client’s DNS information and allow customers to change this information, in fact, also provide dynamic DNS. Most often, the client can change the information by going through the web interface.
The lifetime (TTL) (see RFC 1034) for dynamic recording is made very short (no more than two to three minutes), otherwise other DNS servers will put it in their cache, and when it changes, their clients will receive outdated information for a long time.
Dynamic DNS is also often used in local networks, where clients obtain an IP address via DHCP, and then register their names in a local DNS server.
The protocol for updating DNS is described in RFC 2136 and is implemented, for example, by the nsupdate utility. For secure client authentication, TSIG technology (RFC 2845), which uses a pre-known key, can be used. The disadvantage of this technology is that the key must be installed on each client and server.
For updating, special client programs are usually used, which can also use HTTP GET requests to update data.
Hosting and other companies that store client’s DNS information and allow customers to change this information, in fact, also provide dynamic DNS. Most often, the client can change the information by going through the web interface.