Cisco 3200 Series Hardware Reference Manual page 129

Appendix C Switch Port Functionality
In a typical IOS-managed Layer 2 switch, there would be one Layer 3 Switch Virtual Interface (SVI) that
allows you to configure the device over a Layer 3 protocol by using SNMP or a Telnet application. This
is referred to as the management VLAN for the switch. The default management VLAN is usually the
native VLAN 1. The configurable VLAN device allows you to configure any VLAN to be the
management VLAN, but there can be only one virtual Layer 3 interface in one VLAN.
A switch routing module, like the FESMIC, allows you to use the SVI to configure more than one virtual
Layer 3 interface to support routing between the different VLANs, and the virtual Layer 3 interface of
any other router interface in the system, as shown in
You can manage the switching router with any switch virtual Layer 3 interface created in the system. The
FESMIC router switch port is an interface capable of handling Layer 3 switching functionality in
hardware. The SVI architecture has the framework to support such a functionality.
A SVI represents a VLAN of switch ports as one interface to the routing function in the system.
•
There is at most one SVI associated with a VLAN.
•
It is not necessary to configure an SVI for every known VLAN. It is only necessary to configure a
•
SVI when you want to route between VLANs or want to provide IP host connectivity to the rest of
the network by using any of the mobile access router routed interfaces.
• One management SVI, interface VLAN 1, is created at system initialization to permit remote
administration. Additional SVIs exist only when explicitly configured by a user.
Figure C-5
OL-5816-10
Switch Virtual Interface Architecture
Layer 3 Routing
SVI SVI
VLAN 1 VLAN 2
AP AP RP AP
e0/1 e0/2 e0/3 e1/1
Figure C-5.
Unnumbered Unnumbered
SVI
VLAN 3 VLAN N
TP RP
e1/2 e1/3
Cisco 3200 Series Router Hardware Reference
Inter-VLAN Routing
Hardware
Switching
RP
e2/1
C-5