ip address unnumbered

Use ip address unnumbered to configure the current interface as IP unnumbered to borrow an IP address from the specified interface.

Use undo ip address unnumbered to restore the default.

Syntax

ip address unnumbered interface interface-type interface-number

undo ip address unnumbered

Default

The interface does not borrow IP addresses from other interfaces.

Views

Interface view

Predefined user roles

network-admin

mdc-admin

Parameters

interface interface-type interface-number: Specifies an interface from which the current interface can borrow an IP address.

Usage guidelines

Typically, you assign an IP address to an interface either manually or through DHCP. If the IP addresses are not enough, or the interface is used only occasionally, you can configure an interface to borrow an IP address from other interfaces. This is called IP unnumbered, and the interface borrowing the IP address is called IP unnumbered interface.

Loopback interfaces cannot borrow IP addresses of other interfaces, but other interfaces can borrow IP addresses of loopback interfaces.

Multiple interfaces can use the same unnumbered IP address. If an interface has multiple manually configured IP addresses, only the primary IP address manually configured can be borrowed.

You cannot enable a dynamic routing protocol on the interface that has no IP address configured. To enable the interface to communicate with other devices, you must configure a static route to the peer device on the interface.

Examples

# Configure the interface Tunnel 1 to borrow the IP address of VLAN-interface 100.

<Sysname> system-view
[Sysname] interface tunnel 1 mode gre
[Sysname-Tunnel1] ip address unnumbered interface vlan-interface 100