Static routing

It is normally only necessary to configure static routes for unusual cases such as multiple routers or multiple IP subnets located on a network. A typical example might be:

• primary Internet access is through a cable/DSL modem to the ISP
• have an ISDN router on the LAN for connecting to the office.

Take an example. The default route to all non-192.168.0.x addresses (if the LAN is 192.168.0.0/24) is out the WAN port to the ISP. But say, for example. 134.199.0.0 is a special case to get to the office. In this case define a static route, telling the router that 134.199.0.0 should not be accessed via the route to the ISP. Thus, if an attempt to access a device on the 134.199.0.x sub-net, then:

• the Destination IP Address and IP Subnet Mask fields specify that this static route applies to all 134.199.0.x addresses.
• The Gateway IP Address fields specifies that all traffic for these addresses should be forwarded to, say, an ISDN router located at 192.168.0.100.