OSPF Configuration Example 441
cConfigure the area-id of the interface and the interface type
[RouterC-ospf] quit
[RouterC] interface serial 0
[RouterC-Serial0] ospf enable area 0
[RouterC-Serial0] ospf network-type p2mp
[RouterC-Serial0] ospf peer 1.1.1.1
[RouterC-Serial0] ospf peer 1.1.1.2
4Configure Router D:
aConfigure the ip address of interface Serial0, encapsulated into frame relay and
configure frame relay mapping table.
[RouterD] interface serial 0
[RouterD-Serial0] ip address 1.1.1.4 255.0.0.0
[RouterD-Serial0] link-protocol fr
[RouterD-Serial0] fr map IP 1.1.1.5 dlci 401 broadcast
bEnable OSPF
[RouterD] router id 4.4.4.4
[RouterD] ospf enable
[RouterD-ospf] quit
cConfigure the area-id of the interface and the interface type
[RouterD-Serial0] ospf enable area 0
[RouterD-Serial0] ospf network-type p2mp
[RouterD-Serial0] ospf peer 1.1.1.5
5Configure Router E:
aConfigure the ip address of interface Serial0, encapsulated into frame relay and
configure frame relay mapping table.
[RouterE] interface serial 0
[RouterE-Serial0] ip address 1.1.1.5 255.0.0.0
[RouterE-Serial0] link-protocol fr
[RouterE-Serial0] fr map IP 1.1.1.1 dlci 501 broadcast
[RouterE-Serial0] fr map IP 1.1.1.4 dlci 502 broadcast
bEnable OSPF
[RouterE-Serial0] quit
[RouterE] router id 5.5.5.5
[RouterE] ospf enable
cConfigure the area-id of the interface and the interface type
[RouterE-ospf] quit
[RouterE] interface serial 0
[RouterE-Serial0] ospf enable area 0
[RouterE-Serial0] ospf network-type p2mp
[RouterE-Serial0] ospf peer 1.1.1.1
[RouterE-Serial0] ospf peer 1.1.1.4
Configure DR on OSPF
Preference I. Networking requirement
The following example describes the configuration of route preference of several
routers in an OSPF autonomous system. The preference of Router A is 100, the
highest on the network, therefore Router A is selected as DR. Router C is of the
second highest priority, therefore is chosen as BDR. The preference of Router B is
0, which means that it cannot be a DR. Router D has no preference, so the default
value 1 is taken.