Skip to main content

Ddns- How it Works? Own Mail Server? Own Www Server? it is Possible Even in your Home

What is DDNS?

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. To use the service one has register at a DDNS server, e.g.:


It is also needed to have a router capable of sending current IP address to the DDNS server. From the TP-Link offer there may be used access points with integrated routers and ADSL modems, like TP-Link TD-W8910G and TD-W8920G, or routers with ADSL modems - TP-Link TD-8840 or TD-8841.

DNS (Domain Name System)

is a service translating an IP address from numeric to domain name. It means that there is no need to memorize addresses in numeric form such as 62.121.128.13 - you can always use adequate name, for example www.dipol.com.pl. DNS server will translate the numeric address into domain name on request. After the computer which made the request receives the numeric address, it can establish connection with the appropriate computer.

Such communication is possible if the server has a static IP, at which it is always available. A single record in DNS server database establishes relation between the addresses 62.121.128.13 and www.dipol.com.pl. This relation is always valid and invariable, so the client can communicate with the server either through domain name (using DNS translation) or directly via numeric address (bypassing DNS server).

What is a DDNS?

If we wish to run a server for website hosting or accessing CCTV camera, available from any Internet location and we don't have a static IP address but a dynamic one supplied by DHCP server (Neostrada - ADSL service in Poland is a good example of such an option), we have to use DDNS (Dynamic Domain Name System) service.

How does DDNS work?

Neostrada clients do not have a static IP - it is changed periodically. As we have shown above, in this situation it is impossible to run a server, because the current IP address of the server would have been unknown. DNS server, which translates domain name into numeric form, points at one specific IP. Once the IP number changes, the DNS data ceases to be valid. The solution is provided by DDNS service. Similarly to DNS server, it provides a database containing relations between domain and numeric addresses, but this database may be updated on request by the domain owner. Thanks to this feature, the server is available in the domain address regardless its actual IP number. In such a case, the access to the server is limited to its domain name translated by DDNS server, unless we know its actual IP number (but of course we do not know how long it will be valid). 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, and, after the notification is sent to DDNS server, it takes another minute or so to send this piece of data to DNS server to update the database. In result, our server will be periodically unavailable up to several minutes, every time the IP address has been changed.

DDNS service is accessible via a number of providers. Its basic version, sufficient to support the above configuration, is usually free of charge. All devices supporting DDNS usually have several provider addresses preset by default.

About the author :Michal Lepiarz
Labels:

Comments

Post a Comment

Popular posts from this blog

Security Camera System - Buyers Guide

Although the application of CCTV security have not changed very much over the past years, the tools and equipment have significantly. Cameras became smaller, cheaper and better, but the major breakthrough happened in recording equipment. Therefore many customers shopping for complete CCTV monitoring and recording systems are confused by such a verity of available products. Goal of this article is to guide buyers toward best possible and most economical type of CCTV equipment, based on intended implementation and requirements. Selecting the right cameras.It is virtually impossible to describe all types of available ones in this short article. We will focus our attention on most popular and widely used camera types instead. CCTV produce images using CMOS or CCD (Charge Couple Device) chips. Tiny, very low price CCTV cameras usually use CMOS technology, produce poor quality images and have very poor light sensitivity. Decent quality CCTV cameras use CCD technology. The size of the CCD c...
7 comments
Read more

CCTV Camera Systems - IP Vs Analog

CCTV Camera have come a long way since being first presented into the industry in the late 1950's. There are all kinds of CCTV Security Camera now such as dome Security Camera, topic Security Camera, IR Security Camera that can see in the dark and even tiny little pen Security Camera like the Wayne Connection. The wireless protection electronic camera industry has become one of the quickest growing sectors these days since Sept Eleventh. Analogue and IP Security Camera are the two kinds of CCTV Security Camera available currently in the marketplace. And while though analog CCTV Security Camera are still the most widely used kind, the functions and versatility that customers & businesses can gain by using IP CCTV techniques compared to analog are tremendous. Some functions include, Security Camera that run on energy over Ethernet (POE). What this implies is that the electronic camera can be powered and transfer movie nourish all with one Cat5 wire, rather than running a en...
8 comments
Read more

Evolution of CCTV Camera in India

Closed Circuit Television (CCTV) camera is widely used in modern times for surveillance. It is used in all countries for security. India is no exception! You may come across CCTV Camera in India in day-to-day life. Besides, its use is increasing. You may find a great future for CCTV in India. CCTVs are here to stay! CCTV was first designed by the German scientist Walter Brunch in 1942. It was used to monitor the launch of rockets. It, later on, became a part of every rocket launch program. It was used to monitor any technical defects taking place during the launch. United Kingdom (UK) began using the system to monitor public places for crime prevention in 1960s. United States (US) started using the system for crime prevention in public buildings. The use of CCTVs quickly spread to other countries. Largest number of CCTV cameras exists in Europe today. The European Government spends almost two-third of its crime prevention budget in CCTV cameras and Digital Video Recorders (DVRs)....
3 comments
Read more