Cisco Catalyst 3560-X Series, Software Configuration Manual

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Catalyst 3750-X and 3560-X Switch Software Configuration Guide
OL-25303-03
Chapter 1 Configuring Interface Characteristics
Interface Types
10-Gigabit Ethernet Network Module
The C3KX-NM-10GT 10-Gigabit Ethernet Network Module has two 10-Gigabit Ethernet copper ports
that can operate at either 1 Gigabit per second or 10 Gigabits per second. To configure the port speed to
1 Gigabit per second, use the
hw-module switch global configuration command. See the command
reference for command syntax description.
Note 10 Mb/s and 100 Mb/s speeds are not supported on this module.
Connecting Interfaces
Devices within a single VLAN can communicate directly through any switch. Ports in different VLANs
cannot exchange data without going through a routing device. With a standard Layer 2 switch, ports in
different VLANs have to exchange information through a router. By using the switch with routing
enabled, when you configure both VLAN 20 and VLAN 30 with an SVI to which an IP address is
assigned, packets can be sent from Host A to Host B directly through the switch with no need for an
external router (
Figure 1-1 ).
Figure 1-1 Connecting VLANs with the 3750-X or 3560-X Switch
When the IP services feature set is running on the switch or the active switch, the switch uses two
methods to forward traffic between interfaces: routing and fallback bridging. If the IP base feature set is
on the switch or the active 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 IPv4
packets with Ethernet II encapsulation are routed in hardware. Non-IP traffic and traffic with other
encapsulation methods are 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 1, “Configuring
IP Unicast Routing,” Chapter 1, “Configuring IP Multicast Routing,” and Chapter 1, “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
Host A
SVI 1 172.20.128.1 172.20.129.1 SVI 2
Layer 3 switch
with routing enabled
VLAN 20
Host B
VLAN 30
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