Technical data

124 CHAPTER 5: IP ROUTING PROTOCOL OPERATION
Example: OSPF
Configuration
Configuring DR Election Based on OSPF Priority
In this example, four Switch 7700 routers, Switch A, Switch B, Switch C, and
Switch D, which can perform the router functions and run OSPF, are located on
the same segment, as shown in
Figure 6.
Figure 6 Configuring DR Election Based on OSPF Priority
The commands listed in the following examples enable Switch A and Switch C to
be DR and BDR. The priority of Switch A is 100, which is the highest on the
network, so it is elected as the DR. Switch C has the second highest priority, so it is
elected as the BDR. The priority of Switch B is 0, which means that it cannot be
elected as the DR, and Switch D does not have a priority, which takes 1 by default.
1 Configure Switch A:
[Switch A] interface Vlan-interface 1
[Switch A-Vlan-interface1] ip address 196.1.1.1 255.255.255.0
[Switch A-Vlan-interface1] ospf dr-priority 100
[Switch A] router id 1.1.1.1
[Switch A] ospf
[Switch A-ospf-1] area 0
[Switch A-ospf-1-area-0.0.0.0]network 196.1.1.0 0.0.0.255
2 Configure Switch B:
[Switch B] interface Vlan-interface 1
[Switch B-Vlan-interface1] ip address 196.1.1.2 255.255.255.0
[Switch B-Vlan-interface1] ospf dr-priority 0
[Switch B] router id 2.2.2.2
[Switch B] ospf
[Switch B-ospf-1] area 0
[Switch B-ospf-1-area-0.0.0.0] network 196.1.1.0 0.0.0.255
3 Configure Switch C:
[Switch C] interface Vlan-interface 1
Display the information of OSPF ABR and
ASBR
display ospf [ process-id ] abr-asbr
Display OSPF interface information display ospf [ process-id ] interface
Display OSPF errors display ospf [ process-id ] error
Table 53 Displaying and Debugging OSPF
Operation Command
Switch A
1.1.1.1
DR
Switch D
Switch B
Switch C
4.4.4.4
2.2.2.2
3.3.3.3
BDR
196.1.1.4/24
196.1.1.3/24196.1.1.2/24
196.1.1.1/24