Example for Configuring IP Address Unnumbered on an Interface

This section provides an example for configuring IP address unnumbered on an interface.

Networking Requirements

As shown in Figure 1, an enterprise builds its intranet through an integrated services digital network (ISDN). DeviceA and DeviceB connect to a local LAN through GE 0/1/0 and connect to each other over the ISDN through dialing interfaces GE 0/1/8. To save IP address resources, the dialing interfaces are configured to borrow IP addresses from GE 0/1/0.

Figure 1 Configuring IP address unnumbered on an interface

Interfaces 1 and 2 in this example represent GE 0/1/0, and GE 0/1/8, respectively.

Precautions

None

Configuration Roadmap

The configuration roadmap is as follows:

Configure IP addresses to be borrowed.
Configure interfaces to borrow IP addresses from other interfaces.

Data Preparation

To complete the configuration, you need the following data:

IP addresses of the numbered interfaces
Numbers of the numbered interfaces

Procedure

Configure DeviceA.

# Configure an IP address for GE 0/1/0.

<HUAWEI> system-view
[~HUAWEI] sysname DeviceA
[*HUAWEI] commit
[~DeviceA] interface gigabitethernet 0/1/0
[~DeviceA-GigabitEthernet0/1/0] ip address 172.16.10.1 255.255.255.0
[*DeviceA-GigabitEthernet0/1/0] undo shutdown
[*DeviceA-GigabitEthernet0/1/0] quit

# Configure GE 0/1/8 to borrow the IP address from GE 0/1/0.

[*DeviceA] interface GigabitEthernet 0/1/8
[*DeviceA-GigabitEthernet0/1/8] ip address unnumbered interface gigabitethernet 0/1/0
[*DeviceA-GigabitEthernet0/1/8] undo shutdown
[*DeviceA-GigabitEthernet0/1/8] quit

Configure DeviceB.

# Configure an IP address for GE 0/1/0.

<HUAWEI> system-view
[~HUAWEI] sysname DeviceB
[*HUAWEI] commit
[~DeviceB] interface gigabitethernet 0/1/0
[~DeviceB-GigabitEthernet0/1/0] ip address 172.16.20.1 255.255.255.0
[*DeviceB-GigabitEthernet0/1/0] undo shutdown
[*DeviceB-GigabitEthernet0/1/0] quit

# Configure GE 0/1/8 to borrow the IP address from GE 0/1/0.

[*DeviceB] interface GigabitEthernet 0/1/8
[*DeviceB-GigabitEthernet0/1/8] ip address unnumbered interface gigabitethernet 0/1/0
[*DeviceB-GigabitEthernet0/1/8] undo shutdown
[*DeviceB-GigabitEthernet0/1/8] quit

# Configure a route to the Ethernet network segment of Device B.

[*DeviceB] ip route-static 172.16.10.0 255.255.255.0 GigabitEthernet 0/1/8
[*DeviceB] commit

Verify the configuration.

# Ping the IP address of DeviceB's interface that directly connects to DeviceA from DeviceA. The ping operation is successful.

[~DeviceA] ping 172.16.20.1
  PING 172.16.20.2: 56  data bytes, press CTRL_C to break
    Reply from 172.16.20.2: bytes=56 Sequence=1 ttl=255 time=25 ms
    Reply from 172.16.20.2: bytes=56 Sequence=2 ttl=255 time=25 ms
    Reply from 172.16.20.2: bytes=56 Sequence=3 ttl=255 time=26 ms
    Reply from 172.16.20.2: bytes=56 Sequence=4 ttl=255 time=26 ms
    Reply from 172.16.20.2: bytes=56 Sequence=5 ttl=255 time=26 ms
  --- 172.16.20.2 ping statistics ---
    5 packet(s) transmitted
    5 packet(s) received
    0.00% packet loss
    round-trip min/avg/max = 25/25/26 ms

Configuration Files

DeviceA configuration file

#
 sysname DeviceA
#
interface GigabitEthernet0/1/0
 undo shutdown
 ip address 172.16.10.1 255.255.255.0
#
interface GigabitEthernet0/1/8
 undo shutdown
 ip address unnumbered interface GigabitEthernet0/1/0
#
ip route-static 172.16.20.0 255.255.255.0 GigabitEthernet0/1/8
#
return

DeviceB configuration file

#
 sysname DeviceB
#
interface GigabitEthernet0/1/0
 undo shutdown
 ip address 172.16.20.1 255.255.255.0
#
interface GigabitEthernet0/1/8
 undo shutdown
 ip address unnumbered interface GigabitEthernet0/1/0
#
ip route-static 172.16.10.0 255.255.255.0 GigabitEthernet0/1/8
#
return