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Catalyst 3560 Switch Software Configuration Guide
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Chapter 11 Configuring Interface Characteristics
Using Interface Configuration Mode
Figure 11-1 Connecting VLANs with the Catalyst 3560 Switch
When the IP services image is running on the switch, the switch supports two methods of forwarding
traffic between interfaces: routing and fallback bridging. If the IP base image is on the switch, only basic
routing (static routing and RIP) is supported. Whenever possible, to maintain high performance,
forwarding is done by the switch hardware. However, only IP Version 4 packets with Ethernet II
encapsulation can be routed in hardware. Non-IP traffic and traffic with other encapsulation methods can
be fallback-bridged by hardware.
The routing function can be enabled on all SVIs and routed ports. The switch routes only IP traffic.
When IP routing protocol parameters and address configuration are added to an SVI or routed port,
any IP traffic received from these ports is routed. For more information, see Chapter 36,
“Configuring IP Unicast Routing,” Chapter 44, “Configuring IP Multicast Routing,” and
Chapter 45, “Configuring MSDP.
Fallback bridging forwards traffic that the switch does not route or traffic belonging to a nonroutable
protocol, such as DECnet. Fallback bridging connects multiple VLANs into one bridge domain by
bridging between two or more SVIs or routed ports. When configuring fallback bridging, you assign
SVIs or routed ports to bridge groups with each SVI or routed port assigned to only one bridge
group. All interfaces in the same group belong to the same bridge domain. For more information,
see Chapter 46, “Configuring Fallback Bridging.”
Using Interface Configuration Mode
The switch supports these interface types:
Physical ports—switch ports and routed ports
VLANs—switch virtual interfaces
Port channels—EtherChannel interfaces
You can also configure a range of interfaces (see the “Configuring a Range of Interfaces” section on
page 11-11).
To configure a physical interface (port), specify the interface type, module number, and switch port number,
and enter interf ace configuration mode.
Type—Fast Ethernet (fastethernet or fa) for 10/100 Mb/s Ethernet, Gigabit Ethernet (gigabitethernet
or gi) for 10/100/1000 Mb/s Ethernet ports, or small form-factor pluggable (SFP) module Gigabit
Ethernet interfaces.
Host A
SVI 1172.20.128.1 172.20.129.1SVI 2
Layer 3 switch
with routing enabled
VLAN 20
Host B
VLAN 30
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