36-4
Catalyst 3560 Switch Software Configuration Guide
OL-8553-06
Chapter 36 Configuring IP Unicast Routing
Configuring IP Addressing
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, 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 36-4
Assigning IP Addresses to Network Interfaces, page 36-5
Configuring Address Resolution Methods, page 36-8
Routing Assistance When IP Routing is Disabled, page 36-10
Configuring Broadcast Packet Handling, page 36-13
Monitoring and Maintaining IP Addressing, page 36-17

Default Addressing Configuration

Tabl e 36-1 shows the default addressing configuration.
Tab l e 36-1 Default Addressing Configuration
Feature Default Setting
IP address None defined.
ARP No permanent entries in the Address Resolution Protocol (ARP) cache.
Encapsulation: Standard Ethernet-style ARP.
Timeout: 14400 seconds (4 hours).
IP broadcast address 255.255.255.255 (all ones).
IP classless routing Enabled.