Multiple OSPF Instances

OcNOS-SP : Layer 3 Guide : Layer 3 Unicast Configuration Guide : OSPFv2 : Multiple OSPF Instances

By using multiple OSPF instances, OSPF routes can be segregated, based on their instance number. Routes of one instance are stored differently from routes of another instance running in the same router.

To configure multiple OSPF instances, perform the following procedures referring to the topology diagram below:

1. Enable OSPF on an interface.

2. Enable multiple instances.

3. Configure redistribution among multiple instances.

Note: Optionally, redistribution can be configured with the metric, type or route-map options.

Topology

Figure 8-72: Multiple OSPF Instances

Enable Multiple OSPF Instances on a Router

In this example, routers R1, R2, and R3 are in Area 0, and all run OSPF.

(config)#interface eth1	Enter interface mode for eth1.
(config-if)#ip address 2.2.2.2/24	Specify the IP address of the interface.
(config-if)#no shutdown	Activate the interface.
(config-if)#exit	Exit interface mode.
(config)#router ospf 10	Configure an OSPF instance with an instance ID of 10.
(config-router)#router-id 5.5.5.5	Configure the router ID to use on this instance.
(config-router)#network 2.2.2.0/24 area 0	Advertise the network with the area ID.
(config-router)#commit	Commit the candidate configuration to the running configuration.

(config)#interface eth1	Enter interface mode for eth1.
(config-if)#ip address 2.2.2.3/24	Specify the IP address of the interface.
(config-if)#no shutdown	Activate the interface.
(config-if)#exit	Exit interface mode.
(config)#router ospf 10	Configure an OSPF instance with an instance ID of 10.
(config-router)#router-id 6.6.6.6	Configure the router ID to use on this instance.
(config-router)#network 2.2.2.0/24 area 0	Advertise the network with the area ID.
(config-router)#exit	Exit router mode.
(config)#interface eth2	Enter interface mode for eth2.
(config-if)#ip address 4.4.4.4/24	Configure the IP address.
(config-if)#no shutdown	Activate the interface.
(config-if)#exit	Exit interface mode.
(config)#router ospf 15	Configure an OSPF instance with an instance ID of 15.
(config-router)#router-id 8.8.8.8	Configure the router ID to use on this instance.
(config-router)#network 4.4.4.0/24 area 0	Advertise the network with the area ID.
(config-router)#commit	Commit the candidate configuration to the running configuration.

(config)#interface eth1	Enter interface mode for eth1.
(config-if)#ip address 4.4.4.5/24	Configure the IP address.
(config-if)#no shutdown	Activate the interface.
(config-if)#exit	Exit interface mode.
(config)#router ospf 15	Configure an OSPF instance with an instance ID of 15.
(config-router)#router-id 7.7.7.7	Configure the router ID to use on this instance.
(config-router)#network 4.4.4.0/24 area 0	Advertise the network with the area ID.
(config-router)#commit	Commit the candidate configuration to the running configuration.

Validation

R1#sh running-config

no service password-encryption

hostname R1

logging monitor 7

ip vrf management

ip domain-lookup

ip pim register-rp-reachability

interface lo

mtu 65536

ip address 127.0.0.1/8

ipv6 address ::1/128

interface eth0

ip address 10.12.26.88/24

interface eth1

ip address 2.2.2.2/24

interface eth2

ip address 10.10.11.10/24

interface eth3

interface eth4

interface eth5

interface eth6

interface eth7

router ospf 10

ospf router-id 5.5.5.5

network 2.2.2.0/24 area 0.0.0.0

line con 0

line vty 0 39

end

R1#sh ip ospf neighbor

Total number of full neighbors: 1

OSPF process 10 VRF(default):

Neighbor ID Pri State Dead Time Address Interface Instance ID

6.6.6.6 1 Full/Backup 00:00:39 2.2.2.3 eth1 0

R1#sh ip ospf route

OSPF process 10:

Codes: C - connected, D - Discard, O - OSPF, IA - OSPF inter area

N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

E1 - OSPF external type 1, E2 - OSPF external type 2

C 2.2.2.0/24 [1] is directly connected, eth1, Area 0.0.0.0

R2#sh running-config

no service password-encryption

hostname R2

logging monitor 7

ip vrf management

ip domain-lookup

ip pim register-rp-reachability

interface lo

mtu 65536

ip address 127.0.0.1/8

ipv6 address ::1/128

interface eth0

ip address 10.12.26.89/24

interface eth1

ip address 2.2.2.3/24

interface eth2

ip address 4.4.4.4/24

interface eth3

interface eth4

interface eth5

interface eth6

router ospf 10

ospf router-id 6.6.6.6

network 2.2.2.0/24 area 0.0.0.0

router ospf 15

ospf router-id 8.8.8.8

network 4.4.4.0/24 area 0.0.0.0

no capability cspf

line con 0

line vty 0 39

end

R2#sh ip ospf neighbor

Total number of full neighbors: 1

OSPF process 10 VRF(default):

Neighbor ID Pri State Dead Time Address Interface Instance ID

5.5.5.5 1 Full/DR 00:00:33 2.2.2.2 eth1 0

Total number of full neighbors: 1

OSPF process 15 VRF(default):

Neighbor ID Pri State Dead Time Address Interface Instance ID

7.7.7.7 1 Full/Backup 00:00:31 4.4.4.5 eth2 0

R2#sh ip ospf route

OSPF process 10:

Codes: C - connected, D - Discard, O - OSPF, IA - OSPF inter area

N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

E1 - OSPF external type 1, E2 - OSPF external type 2

C 2.2.2.0/24 [1] is directly connected, eth1, Area 0.0.0.0

OSPF process 15:

Codes: C - connected, D - Discard, O - OSPF, IA - OSPF inter area

N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

E1 - OSPF external type 1, E2 - OSPF external type 2

C 4.4.4.0/24 [1] is directly connected, eth2, Area 0.0.0.0

R3#sh running-config

no service password-encryption

hostname R3

logging monitor 7

ip vrf management

ip domain-lookup

ip pim register-rp-reachability

interface lo

mtu 65536

ip address 127.0.0.1/8

ipv6 address ::1/128

interface eth0

ip address 10.12.26.90/24

interface eth1

ip address 4.4.4.5/24

interface eth2

ip address 10.10.13.10/24

interface eth3

interface eth4

interface eth5

interface eth6

router ospf 15

ospf router-id 7.7.7.7

network 4.4.4.0/24 area 0.0.0.0

line con 0

line vty 0 39

end

R3#sh ip ospf neighbor

Total number of full neighbors: 1

OSPF process 15 VRF(default):

Neighbor ID Pri State Dead Time Address Interface Instance ID

8.8.8.8 1 Full/DR 00:00:30 4.4.4.4 eth1 0

Redistribute among Multiple Instances

In this example, routes of one instance are redistributed to another instance to enable ping from R1 to R3 or vice versa; and R2 redistributes routes from one instance to another.

(config)#router ospf 15	Configure an OSPF instance with instance ID 15.
(config-router)#router-id 8.8.8.8	Configure the router ID.
(config-router)#redistribute ospf 10	Redistribute instance 10 routes.
(config-router)#redistribute connected	Redistribute connected routes to instance 15.
(config-router)#exit	Exit Router mode, and return to Configure mode.
(config)#router ospf 10	Configure an OSPF instance with instance ID 10.
(config-router)#router-id 6.6.6.6	Configure the router ID.
(config-router)#redistribute ospf 15	Redistribute instance 15 routes.
(config-router)#redistribute connected	Redistribute connected routes to instance 10.
(config-router)#commit	Commit the candidate configuration to the running configuration.

Redistribute with the Metric Option

In this example, on R3, R1 and R2 have each other’s routes with a metric of 100.

(config)#router ospf 15	Configure an OSPF instance with instance ID 15.
(config-router)#router-id 8.8.8.8	Configure the router ID.
(config-router)#redistribute ospf 10 metric 100	Redistribute instance 10 routes with metric 100.
(config-router)#redistribute connected	Redistribute connected routes to instance 15.
(config-router)#exit	Exit Router mode, and return to Configure mode.
(config)#router ospf 10	Configure an OSPF instance with instance ID 10.
(config-router)#router-id 6.6.6.6	Configure the router ID.
(config-router)#redistribute ospf 15 metric 100	Redistribute instance 15 routes with metric 100.
(config-router)#redistribute connected	Redistribute connected routes to instance 10.
(config-router)#commit	Commit the candidate configuration to the running configuration.

Redistribute with the Type Option

In this example, on R3, R1 has R3 routes as type 2, and R2 has R1 routes as type 1.

(config)#router ospf 15	Configure an OSPF instance with instance ID 15.
(config-router)#router-id 8.8.8.8	Configure the router ID.
(config-router)#redistribute ospf 10 metric-type 1	Redistribute instance 10 routes with metric-type 1.
(config-router)#redistribute connected	Redistribute connected routes to instance 15.
(config-router)#exit	Exit Router mode, and return to Configure mode.
(config)#router ospf 10	Configure an OSPF instance with instance ID 10.
(config-router)#router-id 6.6.6.6	Configure the router ID.
(config-router)#redistribute ospf 15 metric-type 2	Redistribute instance 15 routes with type 2.
(config-router)#redistribute connected	Redistribute connected routes to instance 10.
(config-router)#commit	Commit the candidate configuration to the running configuration.

Redistribute with the Route-Map Option

(config)#route-map 1 permit 10	Enter route-map mode, specifying route-map ID.
(config-route-map)#set metric 100	Set metric value.
(config-route-map)#set metric-type type-2	Set metric-type.
(config-route-map)#exit	Exit route-map mode.
(config)#route-map 2 permit 10	Enter route-map mode, specifying route-map ID.
(config-route-map)#set metric 200	Set metric value.
(config-route-map)#set metric-type type-1	Set metric-type.
(config-route-map)#exit	Exit route-map mode.
(config)#router ospf 15	Configure an OSPF instance with instance ID 15.
(config-router)#router-id 8.8.8.8	Configure the router ID.
(config-router)#redistribute ospf 10 route-map 1	Redistribute instance 10 routes with route map 1.
(config-router)#redistribute connected	Redistribute connected routes to instance 15.
(config-router)#exit	Exit Router mode, and return to Configure mode.
(config)#router ospf 10	Configure an OSPF instance with instance ID 10.
(config-router)#router-id 6.6.6.6	Configure the router ID.
(config-router)#redistribute ospf 15 route-map 2	Redistribute instance 15 routes with route map 2.
(config-router)#redistribute connected	Redistribute connected routes to instance 10.
(config-router)#commit	Commit the candidate configuration to the running configuration.

Validation

R1#show ip ospf neighbor

Total number of full neighbors: 1

OSPF process 10 VRF(default):

Neighbor ID Pri State Dead Time Address Interface Instance ID

6.6.6.6 1 Full/DR 00:00:39 2.2.2.3 eth1 0

R2#show ip ospf neighbor

Total number of full neighbors: 1

OSPF process 10 VRF(default):

Neighbor ID Pri State Dead Time Address Interface Instance ID

5.5.5.5 1 Full/Backup 00:00:35 2.2.2.2 eth1 0

Total number of full neighbors: 1

OSPF process 15 VRF(default):

Neighbor ID Pri State Dead Time Address Interface Instance ID

7.7.7.7 1 Full/Backup 00:00:36 4.4.4.5 eth2 0

R3#show ip ospf neighbor

Total number of full neighbors: 1

OSPF process 15 VRF(default):

Neighbor ID Pri State Dead Time Address Interface Instance ID

8.8.8.8 1 Full/DR 00:00:40 4.4.4.4 eth2 0

R1#show ip route

Codes: K - kernel, C - connected, S - static, R - RIP, B - BGP

O - OSPF, IA - OSPF inter area

N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

E1 - OSPF external type 1, E2 - OSPF external type 2

i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2,

ia - IS-IS inter area, E - EVPN,

v - vrf leaked

* - candidate default

IP Route Table for VRF "default"

C 2.2.2.0/24 is directly connected, eth1, 00:08:40

O E1 4.4.4.0/24 [110/201] via 2.2.2.3, eth1, 00:01:18

C 5.5.5.5/32 is directly connected, lo, 00:08:41

O E2 6.6.6.6/32 [110/20] via 2.2.2.3, eth1, 00:01:10

O E2 8.8.8.8/32 [110/20] via 2.2.2.3, eth1, 00:01:10

C 127.0.0.0/8 is directly connected, lo, 00:08:44

C 192.168.20.0/24 is directly connected, eth0, 00:08:40

Gateway of last resort is not set

R2#show ip route

Codes: K - kernel, C - connected, S - static, R - RIP, B - BGP

O - OSPF, IA - OSPF inter area

N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

E1 - OSPF external type 1, E2 - OSPF external type 2

i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2,

ia - IS-IS inter area, E - EVPN,

v - vrf leaked

* - candidate default

IP Route Table for VRF "default"

C 2.2.2.0/24 is directly connected, eth1, 5d00h02m

C 4.4.4.0/24 is directly connected, eth2, 5d00h02m

C 6.6.6.6/32 is directly connected, lo, 4d23h59m

C 8.8.8.8/32 is directly connected, lo, 4d23h59m

C 127.0.0.0/8 is directly connected, lo, 5d00h09m

C 192.168.20.0/24 is directly connected, eth0, 5d00h08m

Gateway of last resort is not set

R3#show ip route

Codes: K - kernel, C - connected, S - static, R - RIP, B - BGP

O - OSPF, IA - OSPF inter area

N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

E1 - OSPF external type 1, E2 - OSPF external type 2

i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2,

ia - IS-IS inter area, E - EVPN,

v - vrf leaked

* - candidate default

IP Route Table for VRF "default"

O E2 2.2.2.0/24 [110/20] via 4.4.4.4, eth2, 00:02:45

C 4.4.4.0/24 is directly connected, eth2, 00:07:12

C 5.5.5.5/32 is directly connected, lo, 00:16:35

O E2 6.6.6.6/32 [110/20] via 4.4.4.4, eth2, 00:02:45

O E2 8.8.8.8/32 [110/20] via 4.4.4.4, eth2, 00:02:45

C 127.0.0.0/8 is directly connected, lo, 00:16:39

C 192.168.20.0/24 is directly connected, eth0, 00:15:36

Gateway of last resort is not set

#show ip ospf route

OSPF process 100:

Codes: C - connected, D - Discard, O - OSPF, IA - OSPF inter area

N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

E1 - OSPF external type 1, E2 - OSPF external type 2

C 10.10.9.0/24 [1] is directly connected, eth2, Area 0.0.0.0

C 10.10.10.0/24 [1] is directly connected, eth3, Area 0.0.0.0

O 10.10.11.0/24 [101] via 10.10.10.11, eth3, Area 0.0.0.0

C 10.10.12.0/24 [1] is directly connected, eth1, Area 0.0.0.0

O 10.10.13.0/24 [102] via 10.10.10.11, eth3, Area 0.0.0.0

O 10.10.14.0/24 [102] via 10.10.10.11, eth3, Area 0.0.0.0

R2#show route-map

route-map 1, permit, sequence 10

Match clauses:

Set clauses:

metric 100

metric-type type-2

route-map 2, permit, sequence 10

Match clauses:

Set clauses:

metric 200

metric-type type-1

R1#show ip ospf route

OSPF process 10:

Codes: C - connected, D - Discard, O - OSPF, IA - OSPF inter area

N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

E1 - OSPF external type 1, E2 - OSPF external type 2

C 2.2.2.0/24 [1] is directly connected, eth1, Area 0.0.0.0

E1 4.4.4.0/24 [201] via 2.2.2.3, eth1

E2 6.6.6.6/32 [1/20] via 2.2.2.3, eth1

E2 8.8.8.8/32 [1/20] via 2.2.2.3, eth1

E2 192.168.20.0/24 [1/20] via 2.2.2.3, eth1

R2#show ip ospf route

OSPF process 10:

Codes: C - connected, D - Discard, O - OSPF, IA - OSPF inter area

N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

E1 - OSPF external type 1, E2 - OSPF external type 2

C 2.2.2.0/24 [1] is directly connected, eth1, Area 0.0.0.0

OSPF process 15:

Codes: C - connected, D - Discard, O - OSPF, IA - OSPF inter area

N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

E1 - OSPF external type 1, E2 - OSPF external type 2

C 4.4.4.0/24 [1] is directly connected, eth2, Area 0.0.0.0

R3#show ip ospf route

OSPF process 15:

Codes: C - connected, D - Discard, O - OSPF, IA - OSPF inter area

N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

E1 - OSPF external type 1, E2 - OSPF external type 2

E2 2.2.2.0/24 [1/20] via 4.4.4.4, eth2

C 4.4.4.0/24 [1] is directly connected, eth2, Area 0.0.0.0

E2 6.6.6.6/32 [1/20] via 4.4.4.4, eth2

E2 8.8.8.8/32 [1/20] via 4.4.4.4, eth2

E2 192.168.20.0/24 [1/20] via 4.4.4.4, eth2

Last modified date: 10/16/2023