# Network elements

Network elements represent included IP addresses in Security Engine configurations.

Table 1. Types of network elements
Element Type | Explanation
--- | ---
Address Ranges | Define a set of consecutive IP addresses between a start address and end address that you define.
Aliases | Context-dependent elements with no fixed value. The value is defined per engine and is determined when a policy containing the Alias is installed.
Countries | Country elements contain lists of IP addresses registered in a particular country.
Domain Names | The name of an Internet domain that is automatically resolved by an Security Engine to all IP addresses associated with the domain.
Expressions | Allow defining IP addresses using logical operators, which simplify the definition of complex sets of addresses.
Groups | Allow collecting together other Network Elements of any type. Represents all IP addresses defined in the included elements.
Hosts | Represent a single IP address.
IP Address Lists | Represent a list of IP addresses.
Networks | Represent a complete (sub)network of addresses.
Security Engines | Configurations particular to individual Security Engines, such as the interface configuration.
Routers | Represent a next-hop router in configurations where required. In policies, represent a single IPv4 or IPv6 address.
Servers | Represent an SMC server or an external server that provides a service to the system. In policies, represent a single IP address.
Zones | Interface reference that can combine several network interfaces of Security Engines into one logical entity. Used for defining interface matching requirements in traffic handling rules in policies.