Services and TCP ports There are a number of different services and protocols in use on the Internet. The most commonly known is HTTP which is used by web servers to transmit requests and responses for unencrypted web pages. These services are set up to listen for requests on a numbered port. These services and […]

NAT NAT or Network Address Translation is the process that enables a single device such as a router or firewall to act as an agent between the Internet or Public Network and a local or private network. This “agent”, in real time, translates the source IP address of a device on one network interface, usually […]

IPv6 Internet Protocol version 6 (IPv6) will succeed IPv4 as the standard networking protocol of the Internet. IPv6 provides a number of advances over IPv4 but the primary reason for its replacing IPv4 is its limitation in addresses. IPv4 uses 32 bit addresses which means there is a theoretical limit of 2 to the power […]

Interfaces and Zones A Firewall is a gateway device that may be the nexus point for more than 2 networks. The interface that the traffic is coming in on and should be going out on is a fundamental concern for the purposes of routing as well as security. Routing, policies and addresses are all associated […]

How Packets are handled by FortiOS To give you idea of what happens to a packet as it makes its way through the FortiGate unit here is a brief overview. This particular trip of the packet is starting on the Internet side of the FortiGate firewall and ends with the packet exiting to the Internal […]

FortiGate Modes The FortiGate unit has a choice of modes that it can be used in, either NAT/Route mode or Transparent mode. The FortiGate unit is able to operate as a firewall in both modes, but some of its features are limited in Transparent mode. It is always best to choose which mode you are […]

Firewall concepts There are a number of foundational concepts that are necessary to have a grasp of before delving into the details of how the FortiGate firewall works. Some of these concepts are consistent throughout the firewall industry and some of them are specific to more advanced firewalls such as the FortiGate. Having a solid […]

How does a FortiGate Protect Your Network? The FortiGate firewall protects your network by taking the various components and using them together to build a kind of wall or access control point so that anyone that is not supposed to be on your network is prevented from accessing your network in anyway other than those […]