3Com 5500G, 4210, 4200G manual Area Network 196.1.1.0

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.