Internet gateway is a host (or a server) at the boundary of LAN and the Internet. In this example, a server with Windows will be used. The Kerio Control firewall (see chapter 2.3 Kerio Control installation) as well as Kerio Connect will be installed on this server. Kerio Connect will be used as a mailserver and groupware server.
Follow the ISP's instructions to set the interface connected to the Internet. Most ISP use automatic configuration of TCP/IP parameters by using DHCP protocol. In case of manual configuration, the following parameters are required for proper functionality of the Internet interface: IP address, subnet mask, default gateway and at least one DNS server's address.
The web interface of the company headquarter's firewall should have a fixed IP address to make it possible for the filial's server and VPN clients to connect to it (see requirements in chapter 1 Introduction). Suppose that the ISP has aasigned IP adddress 85.17.210.230
. It is also recommended to assign a DNS name (e.g. server.company.com
) to this IP address; otherwise all VPN clients will be required to define the server by the IP address.
Verify connectivity (i.e. by using the ping
command or by opening a Web site using your browser).
The following parameters will be set at the LAN Interface:
IP address we will use the 192.168.1.1
IP address (refer to chapter 2.1 Selection of IP addresses for LAN).
network mask — 255.255.255.0
default gateway — no default gateway is allowed at this interface!
DNS server — no DNS server should be set on this interface.