Non-Forwarding IP Management Interfaces

Multiple IP interface configuration provides the ability to assign a unique IP address to each non-routing interface on the switch. The ability to set a unique IP address on each VLAN configured on the switch means that host management can be accessed from any VLAN configured with its own IP address.

The ability to assign an IP subnet to an interface that is separate from the subnet that is passing data through the switch, allows the network administrator to create an out-of-band management subnet designed to only pass network management data.

Note

All interfaces can be configured as either a routing interface or a non-forwarding IP interface. It is recommended that you only use the non-routing multiple IP interface feature on a non-routing switch: a switch that does not have any routing capability turned on and is not directly connected to a router.

A non-routing host management IP interface can now be configured:

• In interface configuration command mode using the interface command
• In any command mode using an enhanced set ip address command

When configuring the non-routing host management IP interface in interface configuration command mode you must explicitly set the interface as a non-forwarding interface using the no ip forwarding command for IPv4 forwarding. IPv6 forwarding is disabled by default. On an IPv4 interface, you must disable IP Proxy ARP using the no ip proxy-arp command.

When configuring a non-routing host management IPv4 and IPv6 interfaces in any command mode, use the set ip address command. The IP address is assigned to the specified interface. The set ip address command automatically configures the specified interface to disable both IP forwarding and IP Proxy ARP for IPv4. IPv6 forwarding is disabled by default and IPv6 proxy is not supported. This command can only be used in a non-routing host management IP interface context.

The set ip address command only allows for the specifying of a primary IPv4 address or an IPv6 address. If you wish to configure a non-forwarding IP interface with secondary IP addresses, use the interface command in configuration command mode to configure the interface. IPv6 addressing makes no distinction between primary and secondary addresses and treats IPv6 addresses equally.

When clearing an IPv4 or IPv6 address, the IP address to be cleared is explicitly stated. This command can be used on a primary IPv4 address or any IPv6 address. Use the no ip address command in interface configuration command mode to clear a secondary IP address.

Use the clear ip interface command to clear the IP interface the IP address is assigned to.

The following example clears the IP interface VLAN 5:

System(rw)->clear ip interface vlan.0.5