Secondary IP Interfaces

Table 1. Secondary IP Interfaces product support

Feature

Product

Release introduced

Secondary IP Interfaces

5320 Series

Fabric Engine 8.10

Only 5320-48P-8XE and 5320-48T-8XE support more than one VRF with IP configuration.

5420 Series

Fabric Engine 8.10

5520 Series

Fabric Engine 8.10

5720 Series

Fabric Engine 8.10

7520 Series

Fabric Engine 8.10

7720 Series

Fabric Engine 8.10

VSP 4900 Series

VOSS 8.10

VSP 7400 Series

VOSS 8.10

The ability to add Secondary IP Interfaces on a Layer 2 VLAN means that you can have both primary and secondary IP subnets as local routes and increase the number of connected hosts. This feature is useful for subnets that have used all available host IP addresses.

You can configure Secondary IP Interfaces on VLAN interfaces only; you cannot configure a Secondary IP Interface for a brouter port or CLIP interface. Both the Global Router (VRF 0) and user-defined VRFs support Secondary IP Interfaces on associated VLANs. The secondary addresses share the same routeable MAC with the primary IP address.

A VLAN interface can support up to 32 secondary IP addresses. The total number of secondary IP addresses you can create on the same switch depends on available resources. For scaling information, see Fabric Engine Release Notes.

DHCP Smart Relay makes DHCP Relay aware of Secondary IP Interfaces. DHCP Smart Relay can also work with a subset of VRRP addresses. For more information, see DHCP Smart Relay for Secondary IP Interfaces.

Configuration Rules

For more information, see the following tasks: