HDLC in conjunction with IP unnumbered interface configuration example

As shown in Figure 74, Router A and Router B are connected through their POS ports with HDLC enabled.

Configure POS 5/0 of Router A to borrow the IP address of the local loopback interface, whose IP address has a 32-bit mask.

Configure Router A to learn the routing information of Router B through static routes, so that Router A can reach the network segment 12.1.2.0/24.

1. Configure Router A:

   <RouterA> system-view
   [RouterA] interface loopback 1
   [RouterA-LoopBack1] ip address 12.1.1.2 32
   [RouterA-LoopBack1] quit
   [RouterA] interface pos 5/0
   [RouterA-Pos5/0] clock master
   [RouterA-Pos5/0] link-protocol hdlc
   [RouterA-Pos5/0] ip address unnumbered interface loopback 1
   [RouterA-Pos5/0] quit
   

2. Configure Router B:

   <RouterB> system-view
   [RouterB] interface pos 5/0
   [RouterB-Pos5/0] link-protocol hdlc
   [RouterB-Pos5/0] ip address 12.1.1.1 24
   

3. Configure a static route on Router A:

   [RouterA] ip route-static 12.1.1.0 24 pos 5/0
   [RouterA] ip route-static 12.1.2.0 24 12.1.1.1
   

4. Verify that Router A can ping network segment 12.1.2.0/24:

   [RouterA] ping 12.1.2.1
     PING 12.1.2.1: 56  data bytes, press CTRL_C to break
       Reply from 12.1.2.1: bytes=56 Sequence=1 ttl=255 time=35 ms
       Reply from 12.1.2.1: bytes=56 Sequence=2 ttl=255 time=1 ms
       Reply from 12.1.2.1: bytes=56 Sequence=3 ttl=255 time=10 ms
       Reply from 12.1.2.1: bytes=56 Sequence=4 ttl=255 time=1 ms
       Reply from 12.1.2.1: bytes=56 Sequence=5 ttl=255 time=1 ms
   
     --- 12.1.2.1 ping statistics ---
       5 packet(s) transmitted
       5 packet(s) received
       0.00% packet loss
       round-trip min/avg/max = 1/9/35 ms
   

   # Execute the display ip routing-table command on Router A to see that the routing table information is correct.

   [RouterA] display ip routing-table
   Routing Tables: Public
            Destinations : 5        Routes : 5
   
   Destination/Mask    Proto  Pre  Cost         NextHop         Interface
   
   12.1.1.0/24         Static 60   0            12.1.1.2        POS5/0
   12.1.1.2/32         Direct 0    0            127.0.0.1       InLoop0
   12.1.2.0/24         Static 60   0            12.1.1.1        POS5/0
   127.0.0.0/8         Direct 0    0            127.0.0.1       InLoop0
   127.0.0.1/32        Direct 0    0            127.0.0.1       InLoop0