How to connect two different location servers?

You're looking for a VPN - Virtual Private Network.

VPN transfers the packets of the internal network as payload in an external network connection. The method is called tunneling. To preserve privacy of the internal network, the packets are encrypted before being loaded into the external network packets.

There are a couple of HOWTOs about VPN in the Linux Documentation Project. The explain the basica prety well, but all are quite outdated.

My favourite for Linux-to-Linux VPN in OpenVPN . It works with recent Windowses and many Unix-like systems, too.

We have different servers at both locations, we are using different subnets, for example one location had DSL and connected all PC's to LAN using 172.16.35 subnet and other location had cable modem and Router, again all PC's to LAN using 172.16.16 subnet, now we have to access machines at both locations, how can we do that. thanks.

Did you see the reply from Tauno Voipio?

DS

You can use a Virtual Private Network, to connect the two sites. I use OpenVPN. You can also build a firewall/router/NAT with Linux, to protect your network from the outside world. You can use the same Linux box for both.

He referenced Mssr. Voipio's post in the headers, which means that he did indeed see it, so it seems like the OP wants to have the HOWTO read to him.

In OpenVPN, there are two ways to connect the networks:

- routed, or - bridged.

The bridged connection forwards the datalink level frames, i.e. Ethernet frames. This makes the computers seem in a common local net, which may be an advantage, if protocols like Novell or Microsoft (without TCP/IP) have to be handled. The obvious disadvantage is hefty overhead of unnecessary packets bridged to the other end.

The routed connection routes IP packets over the VPN. It works like any IP routing, connecting different subnets.

It seems to me that you're looking for a routed VPN.

Please get the HOWTOs and read them

HTH