3com 4210 User Manual

Page of 336
Configuring OSPF DR Election
105
area 0.0.0.0
network 196.1.1.0 0.0.0.255 
Perform the following configuration on Switch B.
#
router id 2.2.2.2
#
vlan 1
#
interface Vlan-interface 1
ip address 196.1.1.2 255.255.255.0
ospf dr-priority 0
#
ospf 1
area 0.0.0.0
network 196.1.1.0 0.0.0.255 
Perform the following configuration on Switch C.
#
router id 3.3.3.3
#
vlan 1
#
interface Vlan-interface 1
ip address 196.1.1.3 255.255.255.0
ospf dr-priority 2
#
ospf 1
area 0.0.0.0
network 196.1.1.0 0.0.0.255 
Perform the following configuration on Switch D.
#
router id 4.4.4.4
#
vlan 1
#
interface Vlan-interface 1
ip address 196.1.1.4 255.255.255.0
#
ospf 1
area 0.0.0.0
network 196.1.1.0 0.0.0.255 
Precautions
The DR election is performed only on broadcast and NBMA interfaces rather 
than P2P or P2MP interfaces.
A DR is an interface of a router and belongs to a single network segment. A 
router’s interface may be a DR, while another interface of the router may be a 
BDR or DRother.
 The DR priority of a router interface affects the DR and BDR election. However, 
it does not effect the election immediately after the DR and BDR election ends. 
A new DR priority assigned to a router interface takes effect at the time of next 
DR and BDR election.
A DR may not be a router interface with the highest priority in a network, and 
a BDR may not be a router interface with the second highest priority.