System & Monitor : Device Settings : Dynamic Objects : Host
Host
Host is a logical building block used in defining security policies or NAT. By default, the numbers of hosts equal to the ports in the device are already created.
Host represents various types of addresses, including IP addresses, networks and Ethernet MAC addresses.
Hosts allow entities to be defined once and then be re-used in multiple refrential instances throughout the configuration. For example, an internal Mail Server with an IP address as 192.168.1.15. Rather than repeated use of hte IP address while constructing security policies or NAT Policies, it allows creating a single entity called "Internal Mail Server" as a Host name with an IP address as 192.168.1.15. This host, "Internal Mail Server" can then be easily selected in any configuration screen that uses Hosts as a defining criterion.
By using hosts instead of numerical addresses, you only need to make changes in a single location, rather than in each configuration where the IP address appears. Using Hosts reduces the error of entering incorrect IP addresses, makes it easier to change addresses and increases readability.
Administrator can view the list of all the dynamic hosts from System Management > Device Settings > Dynamic Objects > Host .