Configuring super VLANs

Hosts in a VLAN typically use IP addresses in the same subnet. For Layer 3 interoperability with other VLANs, you can create a VLAN interface for the VLAN and assign an IP address to it. This requires a large number of IP addresses.

The super VLAN feature was introduced to save IP addresses. A super VLAN is associated with multiple sub-VLANs. These sub-VLANs use the VLAN interface of the super VLAN (also known as a super VLAN interface) as the gateway for Layer 3 communication.

You can create a VLAN interface for a super VLAN and assign an IP address to it. However, you cannot create a VLAN interface for a sub-VLAN. You can assign a physical port to a sub-VLAN, but you cannot assign a physical port to a super VLAN. Sub-VLANs are isolated at Layer 2.

You can enable Layer 3 communication between sub-VLANs by performing the following tasks:

  1. Create a super VLAN and the super VLAN interface.

  2. Enable local proxy ARP or ND on the super VLAN interface as follows:

    • In an IPv4 network, enable local proxy ARP on the super VLAN interface. The super VLAN can then process ARP requests and replies sent from the sub-VLANs.

    • In an IPv6 network, enable local proxy ND on the super VLAN interface. The super VLAN can forward and process the NS and NA messages sent from the sub-VLANs.