Dynamic DNS in Linux Article Example | Topics and Well Written Essays - 1500 words

Dynamic DNS in Linux - Article Example The Dynamic Host Configuration Protocol (DHCP) allowed enterprises and Internet service providers (ISPs) to assign addresses to computers on the fly as they powered up. The Domain Name System brought a method of distributing the address information automatically online through recursive queries to remote databases configured for each domain. In addition, this helped conserve the address space available, since not all devices might be actively used at all times and addresses could be assigned as needed. This feature required that DNS servers be kept current automatically as well. The first implementations of dynamic DNS fulfilled this purpose. The excessive use of the Internet by all even in people's homes brought a growing shortage of available IP addresses. DHCP became an important tool for ISPs to manage their address spaces for connecting home and small-business end-users with a single IP address each by connecting them through a Network Address Translation (NAT) router. Behind these routers (in the private network) it was possible to reuse address space set aside for these purposes . This, however, broke the end-to-end principle of Internet methods were required to allow private networks, masqueraded by frequently changing IP addresses, to discover their routable 'outside' address and insert it into the domain name system in order to participate in Internet communications more fully. Today, numerous providers, called Dynamic DNS service providers, offer such technology and services on the Internet. They provide a software client program that automates this function. The client program is executed on a computer in the private network. It connects to the service provider's systems and causes those systems to link the discovered public IP address of the home network with a hostname in the domain name system. Depending on the provider, the hostname is registered within a domain owned by the provider or the customer's own domain name. These services can function by a number of mechanisms. Often they use an HTTP service request since even restrictive environments usually allow HTTP service. This group of services is commonly also referred to by the term Dynamic DNS, although it is not the standards-based DNS Update method. However, the latter might be involved in the providers systems. Most home networking routers today have this feature already built into their firmwa re. One of the early routers to support Dynamic DNS was the UMAX UGate-3000 in 1999, which supported the TZO.COM dynamic DNS service. Dynamic DNS Preparation Unlike DSL, most cable modem providers may not allow you to host sites at home by blocking inbound HTTP (TCP port 80) and SMTP mail (TCP port 25) while allowing most other TCP traffic through. Many DDNS providers are aware of this and provide a redirect service to bypass the problem. Under the system, Web queries first hit their servers on the regular TCP ports and then these servers automatically redirect the Web clients to use the IP address of your server on a different TCP port. Registering DDNS Once you have decided to go ahead with DDNS you'll need to choose between the broad categories of Dynamic DNS service. Free Dynamic DNS: Your website name will be a sub domain of the DDNS provider's domain. For example if the DDNS provide