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Web: Example for Configuring OSPF DR Election

You can configure DR priorities of routers for DR election on a broadcast or non-broadcast network. Generally, the router with high performance and reliability is elected as a DR/BDR.

Networking Requirements

As shown in Figure 1, FW_A has the highest priority of 100 on the network and is elected as the DR; FW_C has the second highest priority and is elected as the BDR. FW_B has the priority of 0 and cannot be elected as a DR; no priority is configured for FW_D and therefore FW_D uses the default value (1).

Figure 1 Networking for configuring OSPF DR election

Configuration Roadmap

The configuration roadmap is as follows:

  1. On each FW, configure a router ID, enable OSPF, and specify a network segment.
  2. Check the DR/BDR status of each FW with the default priority.
  3. Configure DR priorities for interfaces and check the DR/BDR status of the interfaces.

Data Planning

To implement the configuration, you need to collect the following data:

  • Router ID (1.1.1.1) and DR priority (100) of FW_A
  • Router ID (2.2.2.2) and DR priority (0) of FW_B
  • Router ID (3.3.3.3) and DR priority (2) of FW_C
  • Router ID (4.4.4.4) and DR priority (1) of FW_D

Procedure

  • Configure FW_A.
    1. Set interface IP addresses and assign the interfaces to security zones.

      1. Choose Network > Interface.

      2. Click of GE0/0/1 and set required parameters.

        Zone

        trust

        IPv4

        IP Address

        192.168.1.1/24
      3. Click OK.

    2. Configure a security policy for transmitting packets on the network.

      1. Choose Policy > Security Policy > Security Policy.

      2. Click Add and configure the Local -> Trust interzone policy.

        Name

        policy_sec_1

        Source Zone

        Local and Trust

        Destination Zone

        Local and Trust

        Action

        Permit
      3. Click OK.

    3. Configure basic OSPF functions.

      1. Choose Network > Route > OSPF.



      2. Click Add to create an OSPF process.



      3. Configure the area where network segment 192.168.1.0 resides as Area 0.

        1. Click of the created OSPF process.
        2. In the OSPFv2 Process ID:1 navigation tree, choose Basic Configuration > Area Settings.
        3. Click Add and configure the area where network segment 192.168.1.0 resides as Area 0.

        4. Click OK.

    4. Configure a DR priority for an interface.

      1. In the OSPFv2 Process ID:1 navigation tree, choose Basic Configuration > Area Settings.
      2. Click of GE 1/0/0.



      3. Select Advanced Settings and set the DR priority to 100.



      4. Click OK.

  • Configure FW_B.
    1. By referring to Step 1 of FW_A, configure IP addresses for interfaces and assign interfaces to security zones.

      Interface Name

      GE0/0/1

      Zone

      trust

      IP Address

      192.168.1.2/24

    2. By referring to Step 2 of FW_A, configure a security policy for packet exchanges on the network.

      Name

      policy_sec_1

      Source Zone

      Local and Trust

      Destination Zone

      Local and Trust

      Action

      Permit

    3. By referring to Step 3 of FW_A, configure basic OSPF functions.

      Add OSPF Process

      Process ID

      1

      Router ID

      2.2.2.2

      Advanced Settings

      Area

      0

      IP Network

      192.168.1.0

      Mask/Wildcard Mask

      0.0.0.255

    4. By referring to Step 4 of FW_A, configure a DR priority for the interface.

  • Configure FW_C.
    1. By referring to Step 1 of FW_A, configure IP addresses for interfaces and assign interfaces to security zones.

      Interface Name

      GE0/0/1

      Zone

      trust

      IP Address

      192.168.1.3/24

    2. By referring to Step 2 of FW_A, configure a security policy for packet exchanges on the network.

      Name

      policy_sec_1

      Source Zone

      Local and Trust

      Destination Zone

      Local and Trust

      Action

      Permit

    3. By referring to Step 3 of FW_A, configure basic OSPF functions.

      Add OSPF Process

      Process ID

      1

      Router ID

      3.3.3.3

      Advanced Settings

      Area

      0

      IP Network

      192.168.1.0

      Mask/Wildcard Mask

      0.0.0.255

    4. By referring to Step 4 of FW_A, configure a DR priority for the interface.

  • Configure FW_D.
    1. By referring to Step 1 of FW_A, configure IP addresses for interfaces and assign interfaces to security zones.

      Interface Name

      GE0/0/1

      Zone

      trust

      IP Address

      192.168.1.4/24

    2. By referring to Step 2 of FW_A, configure a security policy for packet exchanges on the network.

      Name

      policy_sec_1

      Source Zone

      Local and Trust

      Destination Zone

      Local and Trust

      Action

      Permit

    3. By referring to Step 3 of FW_A, configure basic OSPF functions.

      Add OSPF Process

      Process ID

      1

      Router ID

      4.4.4.4

      Advanced Settings

      Area

      0

      IP Network

      192.168.1.0

      Mask/Wildcard Mask

      0.0.0.255

Verification

Before a DR priority is configured:

# Check the DR/BDR status.

[FW_A] display ospf peer
          OSPF Process 1 with Router ID 1.1.1.1
                  Neighbors

 Area 0.0.0.0 interface 192.168.1.1(GigabitEthernet0/0/1)'s neighbors
 Router ID: 2.2.2.2      Address: 192.168.1.2      GR State: Normal
   State: 2-Way  Mode:Nbr is  Master  Priority: 1
   DR: 192.168.1.4  BDR: 192.168.1.3  MTU: 0
   Dead timer due in 32  sec
   Neighbor is up for 00:04:21
   Authentication Sequence: [ 0 ]

 Router ID: 3.3.3.3      Address: 192.168.1.3      GR State: Normal
   State: Full  Mode:Nbr is  Master  Priority: 1
   DR: 192.168.1.4  BDR: 192.168.1.3  MTU: 0
   Dead timer due in 37  sec
   Neighbor is up for 00:04:06
   Authentication Sequence: [ 0 ]

 Router ID: 4.4.4.4      Address: 192.168.1.4      GR State: Normal
   State: Full  Mode:Nbr is  Master  Priority: 1
   DR: 192.168.1.4  BDR: 192.168.1.3  MTU: 0
   Dead timer due in 37  sec
   Neighbor is up for 00:03:53
   Authentication Sequence: [ 0 ]

Check the OSPF neighbors of FW_A. You can view the DR priorities (the default value is 1) and status of the neighbors. FW_D is a DR, and FW_C is a BDR.

After a DR priority is configured:

# Check the DR/BDR status.

<FW_D> display ospf peer

          OSPF Process 1 with Router ID 4.4.4.4
                  Neighbors

 Area 0.0.0.0 interface 192.168.1.4(GigabitEthernet0/0/1)'s neighbors
 Router ID: 1.1.1.1      Address: 192.168.1.1      GR State: Normal
   State: Full  Mode:Nbr is  Slave  Priority: 100
   DR: 192.168.1.4  BDR: 192.168.1.3  MTU: 0
   Dead timer due in 31  sec
   Neighbor is up for 00:11:17
   Authentication Sequence: [ 0 ]

 Router ID: 2.2.2.2      Address: 192.168.1.2      GR State: Normal
   State: Full  Mode:Nbr is  Slave  Priority: 0
   DR: 192.168.1.4  BDR: 192.168.1.3  MTU: 0
   Dead timer due in 35  sec
   Neighbor is up for 00:11:19
   Authentication Sequence: [ 0 ]

 Router ID: 3.3.3.3      Address: 192.168.1.3      GR State: Normal
   State: Full  Mode:Nbr is  Slave  Priority: 2
   DR: 192.168.1.4  BDR: 192.168.1.3  MTU: 0
   Dead timer due in 33  sec
   Neighbor is up for 00:11:15
   Authentication Sequence: [ 0 ]

The DR priorities configured on the interfaces take effect only after the OSPF process restarts. Run the reset ospf 1 process command in the user view to restart the specified OSPF process.

# Check the OSPF neighbor status.

<FW_D> display ospf peer

          OSPF Process 1 with Router ID 4.4.4.4
                  Neighbors

 Area 0.0.0.0 interface 192.168.1.4(GigabitEthernet0/0/1)'s neighbors
 Router ID: 1.1.1.1      Address: 192.168.1.1      GR State: Normal
   State: Full  Mode:Nbr is  Slave  Priority: 100
   DR: 192.168.1.1  BDR: 192.168.1.3  MTU: 0
   Dead timer due in 35  sec
   Neighbor is up for 00:07:19
   Authentication Sequence: [ 0 ]

 Router ID: 2.2.2.2      Address: 192.168.1.2      GR State: Normal
   State: 2-Way  Mode:Nbr is  Master  Priority: 0
   DR: 192.168.1.1  BDR: 192.168.1.3  MTU: 0
   Dead timer due in 35  sec
   Neighbor is up for 00:07:19
   Authentication Sequence: [ 0 ]

 Router ID: 3.3.3.3      Address: 192.168.1.3      GR State: Normal
   State: Full  Mode:Nbr is  Slave  Priority: 2
   DR: 192.168.1.1  BDR: 192.168.1.3  MTU: 0
   Dead timer due in 37  sec
   Neighbor is up for 00:07:17
   Authentication Sequence: [ 0 ]

# Check the OSPF interface status.

<FW_A> display ospf interface

          OSPF Process 1 with Router ID 1.1.1.1
                  Interfaces

 Area: 0.0.0.0
 IP Address      Type         State    Cost  Pri   DR              BDR
 192.168.1.1     Broadcast    DR       1     100   192.168.1.1     192.168.1.3

# Check the OSPF interface status.

<FW_B> display ospf interface

          OSPF Process 1 with Router ID 2.2.2.2
                  Interfaces

 Area: 0.0.0.0
 IP Address      Type         State    Cost  Pri   DR              BDR
 192.168.1.2     Broadcast    DROther  1     0     192.168.1.1     192.168.1.3

If the neighbor is in the Full state, the device has established an adjacency with its neighbor. If the neighbor remains in the 2-Way state, neither of them is the DR or BDR. In this case, they do not need to exchange LSAs.

If the status of the OSPF interface is DROther, the interface is neither a DR nor a BDR.

Configuration Scripts

  • Configuration script of FW_A

    #
 sysname FW_A
#
interface GigabitEthernet0/0/1
 ip address 192.168.1.1 255.255.255.0
 ospf dr-priority 100
#
firewall zone trust
 set priority 85
 add interface GigabitEthernet0/0/1
#                                                                                
security-policy                                                                 
  rule name policy_sec_1                                                        
    source-zone local                                                           
    source-zone trust                                                         
    destination-zone local                                                      
    destination-zone trust                                                    
    action permit            
#
ospf 1 router-id 1.1.1.1
 area 0.0.0.0
  network 192.168.1.0 0.0.0.255
#
return

  • Configuration script of FW_B

    #
 sysname FW_B
#
interface GigabitEthernet0/0/1
 ip address 192.168.1.2 255.255.255.0
 ospf dr-priority 0
#
firewall zone trust
 set priority 85
 add interface GigabitEthernet0/0/1
#                                                                                
security-policy                                                                 
  rule name policy_sec_1                                                        
    source-zone local                                                           
    source-zone trust                                                         
    destination-zone local                                                      
    destination-zone trust                                                    
    action permit
#
ospf 1 router-id 2.2.2.2
 area 0.0.0.0
  network 192.168.1.0 0.0.0.255
#
return

  • Configuration script of FW_C

    #
 sysname FW_C
#
interface GigabitEthernet0/0/1
 ip address 192.168.1.3 255.255.255.0
 ospf dr-priority 2
#
firewall zone trust
 set priority 85
 add interface GigabitEthernet0/0/1
#                                                                                
security-policy                                                                 
  rule name policy_sec_1                                                        
    source-zone local                                                           
    source-zone trust                                                         
    destination-zone local                                                      
    destination-zone trust                                                    
    action permit
#
ospf 1 router-id 3.3.3.3
 area 0.0.0.0
  network 192.168.1.0 0.0.0.255
#
return

  • Configuration script of FW_D

    #
 sysname FW_D
#
interface GigabitEthernet0/0/1
 ip address 192.168.1.4 255.255.255.0
#
firewall zone trust
 set priority 85
 add interface GigabitEthernet0/0/1
#                                                                                
security-policy                                                                 
  rule name policy_sec_1                                                        
    source-zone local                                                           
    source-zone trust                                                         
    destination-zone local                                                      
    destination-zone trust                                                    
    action permit
#
ospf 1 router-id 4.4.4.4
 area 0.0.0.0
  network 192.168.1.0 0.0.0.255
#
return
Parent Topic: Configuration Examples for OSPF
Copyright © Huawei Technologies Co., Ltd.
Copyright © Huawei Technologies Co., Ltd.
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