Switch Virtual Interfaces - Cisco WLC 5700 Series Interface Configuration Manual

Switch Virtual Interfaces

Switch Virtual Interfaces
A switch virtual interface (SVI) represents a VLAN of switch ports as one interface to the routing or bridging
function in the system. Only one SVI can be associated with a VLAN, but you need to configure an SVI for
a VLAN only when you wish to route between VLANs, to fallback-bridge nonroutable protocols between
VLANs, or to provide IP host connectivity to the controller. By default, an SVI is created for the default
VLAN (VLAN 1) to permit remote controller administration. Additional SVIs must be explicitly configured.
You cannot delete interface VLAN 1.
Note
SVIs provide IP host connectivity only to the system; in Layer 3 mode, you can configure routing across SVIs.
Although the switch stack or controller supports a total of 1005 VLANs and SVIs, the interrelationship between
the number of SVIs and routed ports and the number of other features being configured might impact CPU
performance because of hardware limitations.
SVIs are created the first time that you enter the vlan interface configuration command for a VLAN interface.
The VLAN corresponds to the VLAN tag associated with data frames on an ISL or IEEE 802.1Q encapsulated
trunk or the VLAN ID configured for an access port. Configure a VLAN interface for each VLAN for which
you want to route traffic, and assign it an IP address.
When you create an SVI, it does not become active until it is associated with a physical port.
Note
SVIs support routing protocols and bridging configurations.
The IP base feature set supports static routing and RIP. For more advanced routing or for fallback bridging,
Note
enable the IP services feature set on the standalone switch or the active switch. For information about
using the software activation feature to install a software license for a specific feature set, see the Cisco
IOS Software Activation document.
SVI Autostate Exclude
The line state of an SVI with multiple ports on a VLAN is in the up state when it meets these conditions:
• The VLAN exists and is active in the VLAN database on the controller
• The VLAN interface exists and is not administratively down.
• At least one Layer 2 (access or trunk) port exists, has a link in the up state on this VLAN, and is in the
The protocol link state for VLAN interfaces come up when the first switchport belonging to the
Note
corresponding VLAN link comes up and is in STP forwarding state.
Interface Configuration Guide, Cisco IOS XE Release 3E (Cisco WLC 5700 Series)
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spanning-tree forwarding state on the VLAN.
Configuring Interfaces
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