IBM Switch 9077 User Manual

Page 28

IBM 9077 SP Switch Router: Get Connected to the SP Switch

• Minimal routing

A network completely isolated from all other TCP/IP networks requires
only minimal routing. A minimal routing table is usually built by

ifconfig

when the network interfaces are configured. If your network does not have
direct access to other TCP/IP networks, and if you are not using
subnetting, this may be the only routing table you require.

• Static routing

A network with a limited number of gateways to other TCP/IP networks
can be configured with static routing. When a network has only one
gateway, a static route is the best choice. A static routing table is
constructed manually by the system administrator using the

route

command. See Figure 4. Static routing tables do not adjust to network
changes, so they work best where routes do not change.

Figure 4. Table-Based Routing

• Dynamic routing

A network with more than one possible route to the same destination
should use dynamic routing. A dynamic routing table is built from the
information exchanged by the routing protocols. The protocols are
designed to distribute information that dynamically adjusts routes to reflect
changing network conditions. Routing protocols handle complex routing

Destination

Gateway

Transport

Application

Gateway

Source Host

Destination Host

Network Access

192.168.12.2

192.168.12.3

192.168.1.2

192.168.12.0

192.168.1.0

192.168.12.0

192.168.12.3

192.168.12.2

default

192.168.12.1

192.168.1.0

192.168.12.0

192.168.1.5

192.168.12.3

default

192.168.12.1

192.168.1.0

default

192.168.1.2

192.168.1.5