A network route represents an IP subnet. An IP subnet is a group of IP addresses. A host route belongs to a single IP address. Routers use the host routes to reach locally configured IP addresses.
Network route
A network route represents an IP subnet. An IP subnet is a group of IP addresses. The subnet mask of an IP subnet tells the number of IP addresses it represents.
Let us take an example. 192.168.0.0/24 is an IP subnet. The subnet mask of this IP subnet is /24. It represents 256 IP addresses. You can use subnet masks to identify network routes in the routing table. If a route in the routing table has a subnet mask in the range /8 to /30, it is a network route. The valid subnet mask range for network routes is /8 to /30.
Host route
A host route represents a single IP address. A host route always uses the subnet mask /32. If a route in the routing table has the subnet mask /32, it is a host route.
This tutorial is part of the tutorial series "Understanding route types in the routing table.". Other parts of this series are the following.
Chapter 1 The show IP route command on Routers
Chapter 2 Routing table updating methods
Chapter 3 Directly connected routes and Local routes
Chapter 4 Static and Floating Static Routes Explained
Chapter 5 Static and Dynamic routes in the routing table
Chapter 6 Default Route in the Routing Table
Chapter 7 Network Routes and Host Routes Explained
We use the show ip route command to view the routing table entries.
The following table compares the network and host routes.
| Network routes | Host routes |
| A network route belongs to an IP subnet. | A host route belongs to a single IP host. |
| Routing protocols add only network routes to the routing table. | Routing protocols do not add host routes to the routing table. |
| A network route can have any subnet mask value from the range 8 - 30 in the slash notation. | A host route always has a subnet mask value /32 in the slash notation. |
| In decimal notation, it can have any subnet mask from the range 255.0.0.0 to 255.255.255.252. | In decimal notation, it always has the subnet mask 255.255.255.255. |
| Routers use it to forward data packets. | Routers use it to accept remote connections. |
Network and host routes in automatic route configuration
When we assign an IP address to an interface, the router automatically adds two routes to the routing table based on it. These routes are the network and host routes.
Each IP address belongs to an IP subnet. Each IP subnet has a network address. The router adds the IP address's IP subnet's network address to the routing table. In the routing table, these routes are known as directly connected routes. In other words, all directly connected routes are the network routes.
The router also adds the IP addresses of interfaces as they are to the routing table. In the routing table, these routes are known as local routes. In other words, all local routes are the host routes.
Let us take an example.
You assign an IP address 20.0.0.1/8 to the GigabitEthernet0/1. This IP address belongs to the subnet 20.0.0.0/8. The router adds the 20.0.0.0/8 as the directly connected route. It adds 20.0.0.1/32 as the local route. In this example, 20.0.0.0/8 is a network route, and 20.0.0.1/32 is the local route.
