I have given introduction to VPN in some of the mails before. Now I will try to give more data/info along the same lines.
VPN binds together multiple branch offices worldwide, within the same city, country wherever. It really does not count. It could even connect your home and work just 1 mile away. And you can run a VPN even when you have one office by connecting to the office from a home PC or a laptop in a net cafe. The idea is that it will connect together multiple networks. Which means that you can run any application meaning any application remotely. You can access remote Windows shares, run your tally accounts or access your company's mail server. >From the use case angle, VPNs offer wide possibilities and it is a really cool tool. So we are going to target not only businesses with multiple locations, even a business with one office will need it. I will tell you why. They usually have a stores or a godown. If they have a computer there they will need it. And the boss or the IT guy will access it from home. The idea is that although you have got tools like teamviewer, VNC and ssh to do remote connections, they all have restrictions. Teamviewer is the only software that will run from anywhere. You can run a remote teamviwer session and access any computer in any network. But the issue is you cannot access the Windows file share and transfer data. You cannot access the remote FTP or web server. To do that you need VPN. And you cannot run VNC without a static IP. ssh will not work without static IP and so on. You could do ssh remote port forwarding but you require a 3rd node. VPN simplifies everything. But it comes with price attached. Not money. ;) VPN requires a VPN server running in the office and the MODEM should point the DMZ traffic to it. Normally every MODEM has a NAT section and DMZ link where you can add a local IP address where every TCP and UDP port , also ICMP is mapped to from its public interface. The VPN should run on that local IP. Now from anywhere on the Internet you can connect to the office by setting up a VPN to the public IP of the network. Whenever traffic shows up on the public IP it will go to the DMZ host which in turn sets up a VPN and you are set. In other words for a VPN setup you certainly require access to the MODEM to do DMZ forwarding. Since VPN requires incoming traffic to reach it as it is a server inside every site in the VPN network DMZ configuration of MODEM is required. However for client access from remote, this is not needed. It is outgoing traffic which is allowed by every MODEM. -Girish -- Gayatri Hitech http://gayatri-hitech.com _______________________________________________ ILUGC Mailing List: http://www.ae.iitm.ac.in/mailman/listinfo/ilugc
