Dynamic DNS Servers

Sometimes you will get blocked when you try to access remote systems using the IP address itself. May be sometimes you are to check your local web server is running, that you setup in your home and having a dynamic IP address, when you asked your friend to check your server is running properly, and he/she types the url like http://117.193.123.113/mysite/index.php, sometimes he will get blocked from accessing your server, even if you enabled NAT and all done properly.

It is always easy to remember a site name than IP address and also the IP address, if you are having a dynamic IP will change each time (not always) when you reset the modem based on availability of IP addresses. In such cases there are services that provide you the facility of dynamic DNS servers, where you can create your domain, i.e. a sub domain of the service provider's top level domain. You can set the sub domain to point to the IP address you have. You need to update the ip corresponding to the domain each time if it changed (usually if the modem resets).

Suppose the above case, you are having the ip 117.193.123.113 and you want to test your home ftp server then you can create a domain like myhomeftp.dyndns.com and you can set that point to your home PC that is assigned an ip 117.193.123.113 (set up NAT to share the same public ip between modem and PC, so that the service running on your PC will be available to the public).

There are many such providers offering you the dynamic DNS, and i used the same service from dyndns.com for test purpose and also for the company i worked for, to use the ftp server i setup for the company, that I explained in previous article, as it is a static ip no need to update the dns server frequently.

They provides a number of choices for you to select the top level domain, like dyndns.com or homeftp.net etc.

Remote Connect

Sometimes we will be required to configure a remote system, for e.g:- a technical support officer in India will be informed to configure the web server running in US data center, in such cases we will be required to use programs that help in remote connectivity.

For windows (Windows XP/ 2003 server) we have remote desktop connection, that help to connect to a remote windows desktop and we can configure it the same way as we configure our desktop machine.

For that follow the steps

1. Remote desktop connection from Start->All programs->Accessories->Communications->Remote Desktop Connection.
2. You will be prompted for the computer you want connect to, enter the IP address or the domain name of the computer you want connect to (eg:- 59.129.180.121 or myserver.com), if you are trying to connect to a system in the same local area network as yours then enter the system name
3. Click Options and enter the user name and Password
4. Click Connect
5. Then if the details provided are all correct then you will be connected to the remote dektop and you can work on it as the same way as you work with yours
6. Also verify that you have checked the Allow remote assistance invitations to be sent from this computer (Select Start-> Control Panel -> System -> Remote)

At the server side you must setup the system so that it is ready to accept remote desktop connectivity, for that you want do is that

1. Select System from Start->Control Panel
2. Select the Remote tab
3. Check Allow users to connect remotely to this computer
4. Click Apply
5. Also you can select the users who can be permitted to access the computer remotely by selecting the Select remote users
6. Select Windows Firewall from Control panel
7. Select the exceptions tab
8. Check the Remote desktop and click OK

Also check at the server side that you have enabled NAT (is explained in the previous article)