Connecting the router to X.25 public packet network

As shown in Figure 138, Router A, Router B, and Router C are connected to the same X.25 network. The requirements are:

• The IP addresses of the interfaces Serial 2/0 of the three routers are 168.173.24.1/24, 168.173.24.2/24, and 168.173.24.3/24.

• The X.121 addresses assigned to the three routers are 30561001, 30561002, and 30561003.

• The standard window size supported by the packet network: both receiving window and sending window are 5.

• The standard maximum packet size: both the maximum receiving packet size and the maximum sending packet size are 512.

• Channel range: permanent virtual circuit range, incoming-only channel range and outgoing-only channel range are disabled, and two-way channel range is [1, 32].

1. Configure Router A:

   # Assign an IP address for the interface.

   <RouterA> system-view
   [RouterA] interface serial 2/0
   [RouterA-Serial2/0] ip address 168.173.24.1 255.255.255.0
   

   # Access the public packet network, and configure the router to operate in DTE mode.

   [RouterA-Serial2/0] link-protocol x25 dte
   [RouterA-Serial2/0] x25 x121-address 30561001
   [RouterA-Serial2/0] x25 window-size 5 5
   [RouterA-Serial2/0] x25 packet-size 512 512
   [RouterA-Serial2/0] x25 vc-range bi-channel 1 32
   [RouterA-Serial2/0] x25 map ip 168.173.24.2 x121-address 30561002
   [RouterA-Serial2/0] x25 map ip 168.173.24.3 x121-address 30561003
   [RouterA-Serial2/0] shutdown
   [RouterA-Serial2/0] undo shutdown
   

2. Configure Router B:

   # Assign an IP address for the interface.

   <RouterB> system-view
   [RouterB] interface serial 2/0
   [RouterB-Serial2/0] ip address 168.173.24.2 255.255.255.0
   

   # Access the public packet network, and configure the router to operate in DTE mode.

   [RouterB-Serial2/0] link-protocol x25 dte
   [RouterB-Serial2/0] x25 x121-address 30561002
   [RouterB-Serial2/0] x25 window-size 5 5
   [RouterB-Serial2/0] x25 packet-size 512 512
   [RouterB-Serial2/0] x25 vc-range bi-channel 1 32
   [RouterB-Serial2/0] x25 map ip 168.173.24.1 x121-address 30561001
   [RouterB-Serial2/0] x25 map ip 168.173.24.3 x121-address 30561003
   [RouterB-Serial2/0] shutdown
   [RouterB-Serial2/0] undo shutdown
   

3. Configure Router C:

   # Assign an IP address for the interface.

   <RouterC> system-view
   [RouterC] interface serial 2/0
   [RouterC-Serial2/0] ip address 168.173.24.3 255.255.255.0
   

   # Access the public packet network, and configure the router to operate in DTE mode.

   [RouterC-Serial2/0] link-protocol x25 dte
   [RouterC-Serial2/0] x25 x121-address 30561003
   [RouterC-Serial2/0] x25 window-size 5 5
   [RouterC-Serial2/0] x25 packet-size 512 512
   [RouterC-Serial2/0] x25 vc-range bi-channel 1 32
   [RouterC-Serial2/0] x25 map ip 168.173.24.1 x121-address 30561001
   [RouterC-Serial2/0] x25 map ip 168.173.24.2 x121-address 30561002
   [RouterC-Serial2/0] shutdown
   [RouterC-Serial2/0] undo shutdown
   

Ping Router B and Router C from Router A. Check that Router A can reach Router B and Router C.

# Display the X.25 address mapping table on Router A, for example.

[RouterA-Serial2/0] display x25 map
  Interface: Serial2/0(protocol status is UP)
    ip 168.173.24.2  X.121 address:30561002
      Map-type: SVC_MAP  VC-number: 1
      Facility:
    ip 168.173.24.3  X.121 address:30561003
      Map-type: SVC_MAP  VC-number: 1
      Facility: