ip address unnumbered (Mtunnel view)

Function

The ip address unnumbered command enables an interface to borrow an IP address from another interface.

The undo ip address unnumbered command disables an interface from borrowing an IP address from another interface.

By default, an interface is disabled from borrowing an IP address from another interface.

Format

ip address unnumbered interface { unnumif-type unnumif-num | unnumif-name }

undo ip address unnumbered

Parameters

Parameter	Description	Value
unnumif-name	Specifies the name of an interface whose IP address is borrowed.	-
interface unnumif-type unnumif-num	Specifies the type and number of an interface whose IP address is borrowed.	-

Parameter

Description

Value

unnumif-name

Specifies the name of an interface whose IP address is borrowed.

interface unnumif-type unnumif-num

Specifies the type and number of an interface whose IP address is borrowed.

Views

MTI interface view, Mtunnel view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
mvpn	write

Usage Guidelines

Usage Scenario

To save IP address resources, you can configure an interface to borrow an IP address from another interface. If an interface is only occasionally used, it is unnecessary to configure an IP address for the interface. Instead, configure the interface to borrow an IP address from another interface.

The following interfaces support IP borrowing from other interfaces such as Ethernet and loopback interfaces:

Interface encapsulated with PPP
Tunnel interface
Ethernet interfaces and GE sub-interfaces
VLANIF interface
Eth-Trunk sub-interface
Mtunnel interface

Global-VE sub-interfaces and VE sub-interfaces

Prerequisites

The numbered interface has been configured with an IP address using the ip address command or has obtained an IP address through negotiation.

Configuration Impact

After an unnumbered interface borrows an IP address, the interface can use this IP address to communicate with other devices. The display interface command displays the borrowed IP address and its subnet mask.

Precautions

Because an interface with a borrowed IP address does not have its own IP address, the system cannot generate any route for the interface. Therefore, you need to manually configure the route to implement interconnection between Routers.

When configuring IP address unnumbered on an interface, note the following:

The IP address of the numbered interface cannot be a borrowed IP address.
The IP address of the numbered interface can be lent to multiple interfaces.
If the numbered interface has multiple IP addresses, only the primary IP address can be lent.
If the numbered interface is not configured with any IP address, the IP address 0.0.0.0 is borrowed.
The IP address of the virtual loopback interface can be lent to other interfaces, but the virtual loopback interface cannot borrow an IP address from another interface.
If a tunnel interface is not configured to borrow IP addresses of other interfaces, the tunnel interface does not have an IP address by default.

Example

# Configure Tunnel10 to borrow the IP address from LoopBack0.

<HUAWEI> system-view
[~HUAWEI] interface LoopBack 0
[*HUAWEI-LoopBack0] ip address 1.1.1.1 24
[*HUAWEI-LoopBack0] quit
[*HUAWEI] interface Tunnel 10
[*HUAWEI-Tunnel10] ip address unnumbered interface loopback 0