Cisco Catalyst X4232 Installation And Configuration Note page 41

configuration is done on the internal Layer 3 ports from the
Catalyst 4000 Layer 3 Services module console. The trunking option requires you to configure the
internal Layer 2 interfaces from the supervisor engine console as well as the internal Layer 3 ports from
the Layer 3 Services module console. See Figure 10 for a conceptual illustration of trunking.
Figure 10
Switch backplane
Gig3
trunk
Gig1
Option 2: Interfaces as Gigabit EtherChannels
The EtherChannel option builds on the previous trunk configuration when you assign trunks to a shared
EtherChannel. After you create the EtherChannel between the Catalyst 4000 Layer 3 Services module
and a Catalyst 4000 family switch, the channel provides Layer 3 services to one or multiple VLAN
interfaces.
By bundling the two Catalyst 4000 Layer 3 Services module Gigabit Ethernet interfaces into one logical
port-channel interface, you create a shared connection for traffic from the Layer 2 ports to the Layer 3
ports. You can configure Layer 3 VLAN gateways by creating multiple subinterfaces on the same
logical interface. Creating subinterfaces on one logical interface is less complicated than manually
distributing VLANs among multiple physical and logical interfaces on the Catalyst 4000 Layer 3
Services module. See Figure 11 for a conceptual illustration of channeling.
Figure 11
Switch backplane
Channeling
gig3 and 4
78-10164-03
Trunking
Trunk configuration
Gig4
trunk
Logical
WS-X4232-L3
representations
Gig2
Channeling
Channel configuration
Gig3 Gig4
trunk trunk
Logical
WS-X4232-L3
representations
Gig1 Gig2
Installation and Configuration Note for the Catalyst 4000 Layer 3 Services Module
Vlans 3, 4, 5, ...X
gig3.3
gig3.5
gig3.4
gig3.x
WS-X4232-L3
Vlans 3, 4, 5, ...X
Port-channel 1.3
Port-channel 1.5
Port-channel 1.4
Port-channel 1.x
WS-X4232-L3
Configuration Options
Switch backplane
gig4.7
gig4.6
gig4.2
Switch backplane
Logical
port-channel
interfaces
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