Cisco Systems 3750E manual Steps for Configuring Routing, Configuring IP Addressing, 38-5

Chapter 38 Configuring IP Unicast Routing

Steps for Configuring Routing

Steps for Configuring Routing

By default, IP routing is disabled on the switch, and you must enable it before routing can take place. For detailed IP routing configuration information, see the Cisco IOS IP Configuration Guide, Release 12.2

In the following procedures, the specified interface must be one of these Layer 3 interfaces:

•A routed port: a physical port configured as a Layer 3 port by using the no switchport interface configuration command.

•A switch virtual interface (SVI): a VLAN interface created by using the interface vlan vlan_id global configuration command and by default a Layer 3 interface.

•An EtherChannel port channel in Layer 3 mode: a port-channel logical interface created by using the interface port-channelport-channel-numberglobal configuration command and binding the Ethernet interface into the channel group. For more information, see the “Configuring Layer 3 EtherChannels” section on page 37-15.

Note The switch does not support tunnel interfaces for unicast routed traffic.

All Layer 3 interfaces on which routing will occur must have IP addresses assigned to them. See the “Assigning IP Addresses to Network Interfaces” section on page 38-7.

Note A Layer 3 switch can have an IP address assigned to each routed port and SVI. The number of routed ports and SVIs that you can configure is not limited by software. However, the interrelationship between this number and the number and volume of features being implemented might have an impact on CPU utilization because of hardware limitations. To optimize system memory for routing, use the sdm prefer routing global configuration command.

Configuring routing consists of several main procedures:

•To support VLAN interfaces, create and configure VLANs on the switch or switch stack, and assign VLAN membership to Layer 2 interfaces. For more information, see Chapter 13, “Configuring VLANs.”

•Configure Layer 3 interfaces.

•Enable IP routing on the switch.

•Assign IP addresses to the Layer 3 interfaces.

•Enable selected routing protocols on the switch.

•Configure routing protocol parameters (optional).

Configuring IP Addressing

A required task for configuring IP routing is to assign IP addresses to Layer 3 network interfaces to enable the interfaces and allow communication with the hosts on those interfaces that use IP. These sections describe how to configure various IP addressing features. Assigning IP addresses to the interface is required; the other procedures are optional.

•Default Addressing Configuration, page 38-6

•Assigning IP Addresses to Network Interfaces, page 38-7

Catalyst 3750-E and 3560-E Switch Software Configuration Guide

OL-9775-02 38-5