3Com Router User Manual

Configuring OSPF437
Ta b l e 503   Configure Route Import for OSPF
By default, OSPF does not import routes from other domains into the routing 
table.
The protocol attribute specifies the source routing domain that can be imported. 
At present, OSPF can import routes domain such as connected, static, RIP, and 
BGP.
See“Configuring Route Import for OSPF” for the details of routing import.
Configuring Parameters 
when Importing 
External RoutesWhen the routes found by other routing protocols on the router...

438CHAPTER 29: CONFIGURING OSPF
By default, the cost value is 1, and the tag value is 1. The imported route is 
external route Type 2, the interval of importing external route is 1 second and at 
most 150 external routes can be imported in each interval.
Setting Route PreferenceMultiple dynamic routing protocols may be executed on the router at the same 
time, the problem of information sharing and selection between the routing 
protocols can occur. The system sets a priority for every routing protocol....

OSPF Configuration Example439
OSPF Configuration 
ExampleThis section describes several different configurations of OSPF with a suggested 
procedure for each configuration
Configuring OSPF on the 
Point-to-Multipoint 
Network.The configuration for this example includes the following features:
■Router A communicates with Router B through DLCI 101, communicates with 
Router C through DLCI 102, and communicates with Router E through DLCI 
103.
■Router B communicates with Router A through DLCI 201 and...

440CHAPTER 29: CONFIGURING OSPF
[RouterA] interface serial 0
[RouterA-Serial0] ip address 1.1.1.1 255.0.0.0
[RouterA-Serial0] link-protocol fr
[RouterA-Serial0] fr map IP 1.1.1.2 dlci 101 broadcast
[RouterA-Serial0] fr map IP 1.1.1.3 dlci 102 broadcast
[RouterA-Serial0] fr map IP 1.1.1.4 dlci 103 broadcast
bEnable OSPF
[RouterA-Serial0] quit
[RouterA] router id 1.1.1.1
[RouterA] ospf enable
[RouterA-ospf] quit
cConfigure the area-id of the interface and the interface type
[RouterA] interface serial 0...

OSPF Configuration Example441
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...

442CHAPTER 29: CONFIGURING OSPF
II. Networking diagram
Figure 148   Networking diagram of configuring “DR” selection of OSPF preference
III. Configuration procedure
1Configure Router A:
[RouterA] interface ethernet 0
[RouterA-Ethernet0] ip address 192.1.1.1 255.255.255.0
[RouterA-Ethernet0] ospf dr-priority 100
[RouterA-Ethernet0] quit
[RouterA] router id 1.1.1.1
[RouterA] ospf enable 
[RouterA-ospf] interface ethernet 0
[RouterA-Ethernet0] ospf enable area 0
2Configure Router B:
[RouterB] interface...

OSPF Configuration Example443
Run display ospf peer on Router A to show OSPF peer. Note that Router A has 
3 peers.
[RouterA] display ospf peer
The status of every peer is full, which means that Router A has created 
neighboring relation with all peers. Only DR and BDR have created neighboring 
relation with all routers on the network. Router A is DR and Router C is BDR on the 
network. All other peers are DRother, which means that they are neither DR nor 
BDR.
Change the preference of Router B to 200:...

444CHAPTER 29: CONFIGURING OSPF
Configuring an OSPF 
Virtual LinkArea 4 is not directly connected with area 0 in the following diagram. Area 1 
serves as the transit area to connect area 4 and area 0. Configure a virtual link 
between Router B and Router C.
Figure 149   Networking diagram of configuring OSPF virtual link
To configure an OSPF virtual link:
1Configure Router A:
[RouterA] interface ethernet 0
[RouterA-Ethernet0] ip address 192.1.1.1 255.255.255.0
[RouterA-Ethernet0] quit
[RouterA] router id...

OSPF Configuration Example445
[RouterC] router id 3.3.3.3
[RouterC] ospf enable
[RouterC-ospf] interface ethernet 0
[RouterC-Ethernet0] ospf enable area 2
[RouterC-Ethernet0] interface serial 0
[RouterC-Serial0] ospf enable area 1
[RouterC-Serial0] quit
[RouterC] ospf
[RouterC-ospf] vlink peer-id 2.2.2.2 transit-area 1
Configuring OSPF Peer 
AuthenticationVerify peer authentication with simple text algorithm and MD5 algorithm. Simple 
text authentication is used when Router A and Router B exchange route...

446CHAPTER 29: CONFIGURING OSPF
[RouterB] ospf enable 
[RouterB] interface ethernet 0
[RouterB-Ethernet0] ip address 192.1.1.2 255.255.255.0
[RouterB-Ethernet0] ospf enable area 0
[RouterB-Ethernet0] ospf authentication-mode simple 3Com
3Configure Router C:
[RouterC] router id 3.3.3.3
[RouterC] ospf enable 
[RouterC-ospf] interface serial 0
[RouterC-Serial0] ip address 193.1.1.2 255.255.255.0
[RouterC-Serial0] ospf enable area 1
[RouterC-Serial0] ospf authentication-mode md5 3Com 11
Troubleshooting an...