Router Interfaces - 3Com LANPLEX 2500 EXTENDEDPLEX®2500 EXTENDED User Manual

4-4 C 4: R
HAPTER OUTING WITH

Router Interfaces

IP T
ECHNOLOGY
IP Address
Subnet Mask
1 1 1 1 1 1 1 1 1 1 1
Figure 4-3 How a Subnet Mask Is Applied to the IP Address
An example of an IP address that includes network, subnet, and host
parts is 158.101.230.52 with a subnet mask of 255.255.255.0. This address
is divided as follows:
158.101 is the network part
230 is the subnet part
52 is the host part
A router interface is the connection between the router and a subnet.
In traditional routing models, the interface is the same as the port, since
only one interface can exist per port. In the LANplex system's IP routing
model, more than one port can be connected to the same subnet.
Each router interface has an IP address and a subnet mask. This address
defines both the number of the network to which the router interface is
attached and its host number on that network. A router interface's IP
address serves two functions:
The IP address is used when sending IP packets to or from the router
itself.
The IP address defines the network and subnet numbers of the
segment connected to that interface. See Figure 4-4.
Take the IP address
Network
Apply the subnet mask
1 1 1 1 1 1 1 1 1 1 1 1 1
Result = subnet/host boundary
networ
Network
Subnet and Host
0 0 0 0 0 0 0
Subnet subn
Host
0