set vlan constraint

Use this command to apply a constraint to a VLAN.

Syntax

Parameters

Defaults

If not specified, the VLAN constraint will be set to independent.

Mode

All command modes.

Usage

VLAN learning takes place based upon the contents of the VLAN filtering database. There are two types of databases:

• Independent Virtual Local Area Network (VLAN) Learning (IVL): Each VLAN uses its own filtering database. Transparent source address learning performed as a result of incoming VLAN traffic is not made available to any other VLAN for forwarding purposes. This setting is useful for handling devices (such as servers) with NICs that share a common MAC address. One FID is assigned per VLAN. The FID value is the same as the VID it is assigned to. This is the default mode on Extreme Networks switches.
• Shared Virtual Local Area Network (VLAN) Learning (SVL): Two or more VLANs are grouped to share common source address information. This setting is useful for configuring more complex VLAN traffic patterns, without forcing the switch to flood the unicast traffic in each direction. This allows VLANs to share addressing information. It enables ports or switches in different VLANs to communicate with each other (when their individual ports are configured to allow this to occur). One FID is used by two or more VLANs. The FID value defaults to the lowest VID in the filtering database.

See “Appendix F” of the IEEE Std 802.1Q™2011 standard for a detailed discussion of shared and independent VLAN learning modes and when it is appropriate to use the shared mode.