Overview

Routing is the basic element of data communication networks. It is the process of selecting paths on a network along which packets are sent from a source to a destination.

Routes are classified into the following types based on the destination address:

• Network segment route: The destination is a network segment. The subnet mask of an IPv4 destination address is less than 32 bits or the prefix length of an IPv6 destination address is less than 128 bits.
• Host route: The destination is a host. The subnet mask of an IPv4 destination address is 32 bits or the prefix length of an IPv6 destination address is 128 bits.

Routes are classified into the following types based on whether the destination is directly connected to a router:

• Direct route: The router is directly connected to the network where the destination is located.
• Indirect route: The router is indirectly connected to the network where the destination is located.

Routes are classified into the following types based on the destination address type:

• Unicast route: The destination address is a unicast address.
• Multicast route: The destination address is a multicast address.