Routing policy configuration example for IPv4 route redistribution

As shown in Figure 120, Switch B exchanges routing information with Switch A by using OSPF and with Switch C by using IS-IS.

On Switch B, enable route redistribution from IS-IS to OSPF. Use a routing policy to set the cost of route 172.17.1.0/24 to 100 and the tag of route 172.17.2.0/24 to 20.

1. Specify IP addresses for interfaces. (Details not shown.)

2. Configure IS-IS:

   # Configure Switch C.

   <SwitchC> system-view
   [SwitchC] isis
   [SwitchC-isis-1] is-level level-2
   [SwitchC-isis-1] network-entity 10.0000.0000.0001.00
   [SwitchC-isis-1] quit
   [SwitchC] interface vlan-interface 200
   [SwitchC-Vlan-interface200] isis enable
   [SwitchC-Vlan-interface200] quit
   [SwitchC] interface vlan-interface 201
   [SwitchC-Vlan-interface201] isis enable
   [SwitchC-Vlan-interface201] quit
   [SwitchC] interface vlan-interface 202
   [SwitchC-Vlan-interface202] isis enable
   [SwitchC-Vlan-interface202] quit
   [SwitchC] interface vlan-interface 203
   [SwitchC-Vlan-interface203] isis enable
   [SwitchC-Vlan-interface203] quit
   

   # Configure Switch B.

   <SwitchB> system-view
   [SwitchB] isis
   [SwitchB-isis-1] is-level level-2
   [SwitchB-isis-1] network-entity 10.0000.0000.0002.00
   [SwitchB-isis-1] quit
   [SwitchB] interface vlan-interface 200
   [SwitchB-Vlan-interface200] isis enable
   [SwitchB-Vlan-interface200] quit
   

3. Configure OSPF and route redistribution:

   # Configure OSPF on Switch A.

   <SwitchA> system-view
   [SwitchA] ospf
   [SwitchA-ospf-1] area 0
   [SwitchA-ospf-1-area-0.0.0.0] network 192.168.1.0 0.0.0.255
   [SwitchA-ospf-1-area-0.0.0.0] quit
   [SwitchA-ospf-1] quit
   

   # On Switch B, configure OSPF and enable route redistribution from IS-IS to OSPF.

   [SwitchB] ospf
   [SwitchB-ospf-1] area 0
   [SwitchB-ospf-1-area-0.0.0.0] network 192.168.1.0 0.0.0.255
   [SwitchB-ospf-1-area-0.0.0.0] quit
   [SwitchB-ospf-1] import-route isis 1
   [SwitchB-ospf-1] quit
   

   # Display the OSPF routing table on Switch A to view redistributed routes.

   [SwitchA] display ospf routing
   
             OSPF Process 1 with Router ID 192.168.1.1
                      Routing Tables
   
    Routing for Network
    Destination        Cost     Type    NextHop        AdvRouter     Area
    192.168.1.0/24     1        Stub    192.168.1.1    192.168.1.1   0.0.0.0
   
    Routing for ASEs
    Destination        Cost     Type    Tag        NextHop        AdvRouter
    172.17.1.0/24      1        Type2   1          192.168.1.2    192.168.2.2
    172.17.2.0/24      1        Type2   1          192.168.1.2    192.168.2.2
    172.17.3.0/24      1        Type2   1          192.168.1.2    192.168.2.2
   
    Total Nets: 4
    Intra Area: 1  Inter Area: 0  ASE: 3  NSSA: 0
   

4. Configure filtering lists:

   # Configure IPv4 basic ACL 2002 to permit route 172.17.2.0/24.

   [SwitchB] acl basic 2002
   [SwitchB-acl-ipv4-basic-2002] rule permit source 172.17.2.0 0.0.0.255
   [SwitchB-acl-ipv4-basic-2002] quit
   

   # Configure IP prefix list prefix-a to permit route 172.17.1.0/24.

   [SwitchB] ip prefix-list prefix-a index 10 permit 172.17.1.0 24
   

5. Configure a routing policy.

   [SwitchB] route-policy isis2ospf permit node 10
   [SwitchB-route-policy-isis2ospf-10] if-match ip address prefix-list prefix-a
   [SwitchB-route-policy-isis2ospf-10] apply cost 100
   [SwitchB-route-policy-isis2ospf-10] quit
   [SwitchB] route-policy isis2ospf permit node 20
   [SwitchB-route-policy-isis2ospf-20] if-match ip address acl 2002
   [SwitchB-route-policy-isis2ospf-20] apply tag 20
   [SwitchB-route-policy-isis2ospf-20] quit
   [SwitchB] route-policy isis2ospf permit node 30
   [SwitchB-route-policy-isis2ospf-30] quit
   

6. Apply the routing policy to route redistribution:

   # On Switch B, enable route redistribution from IS-IS to OSPF and apply the routing policy.

   [SwitchB] ospf
   [SwitchB-ospf-1] import-route isis 1 route-policy isis2ospf
   [SwitchB-ospf-1] quit
   

   # Display the OSPF routing table on Switch A.

   [SwitchA] display ospf routing
   
             OSPF Process 1 with Router ID 192.168.1.1
                      Routing Tables
   
    Routing for Network
    Destination        Cost     Type    NextHop         AdvRouter     Area
    192.168.1.0/24     1        Transit 192.168.1.1     192.168.1.1   0.0.0.0
   
    Routing for ASEs
    Destination        Cost     Type    Tag         NextHop       AdvRouter
    172.17.1.0/24      100      Type2   1           192.168.1.2   192.168.2.2
    172.17.2.0/24      1        Type2   20          192.168.1.2   192.168.2.2
    172.17.3.0/24      1        Type2   1           192.168.1.2   192.168.2.2
   
    Total Nets: 4
    Intra Area: 1  Inter Area: 0  ASE: 3  NSSA: 0
   

   The output shows that the cost of route 172.17.1.0/24 is 100 and the tag of route 172.17.2.0/24 is 20.