OSPFv3 Multiarea Adjacency

The OSPFv3 Multiarea Adjacency feature allows you to configure a link that multiple Open Shortest Path First version 3 (OSPFv3) areas can share to enable optimized routing. You can add more than one area to an existing OSPFv3 primary interface.

Prerequisites for OSPFv3 Multiarea Adjacency

  • Ensure that Open Shortest Path First version 3 (OSPFv3) is configured on the primary interface.
  • Ensure that the primary interface type is point-to-point.

Restrictions for OSPFv3 Multiarea Adjacency

  • A multiarea interface operates only if OSPFv3 is configured on the primary interface and the OSPFv3 network type of the primary interface is point-to-point.
  • A multiarea interface exists as a logical construct over a primary interface for OSPFv3; however, the neighbor state on the primary interface is independent of the multiarea interface.
  • A multiarea interface establishes a neighbor relationship with the corresponding multiarea interface on the neighboring device. A mixture of multiarea and primary interfaces is not supported.
  • A multiarea interface advertises a point-to-point connection to another device in the device link-state advertisement (LSA) for the corresponding area when the neighbor state is full.
  • A multiarea interface inherits all the OSPFv3 parameters (such as, authentication) from the primary interface. You cannot configure the parameters on a multiarea interface; however, you can configure the parameters on the primary interface.

Information About OSPFv3 Multiarea Adjacency

OSPFv3 Multiarea Adjacency Overview

Open Shortest Path First version 3 (OSPFv3) allows a single physical link to be shared by multiple areas. This creates an intra-area path in each of the corresponding areas sharing the same link. All areas have an interface on which you can configure OSPFv3. One of these interfaces is designated as the primary interface and others as secondary interfaces.

The OSPFv3 Multiarea Adjacency feature allows you to configure a link on the primary interface to enable optimized routing in multiple areas. Each multiarea interface is announced as a point-to-point unnumbered link. The multiarea interface exists as a logical construct over an existing primary interface. The neighbor state on the primary interface is independent of the neighbor state of the multiarea interface. The multiarea interface establishes a neighbor relationship with the corresponding multiarea interface on the neighboring device. You can only configure multiarea adjacency on an interface that has two OSPFv3 speakers.

Use the ospfv3 multi-area command to configure multiarea adjacency on the primary OSPFv3 interface.

How to Configure OSPFv3 Multiarea Adjacency

Configuring OSPFv3 Multiarea Adjacency

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. interface type number
  4. ipv6 enable
  5. ospfv3 multi-area multi-area-id
  6. ospfv3 multi-area multi-area-id cost interface-cost
  7. ospfv3 process-id ipv6 area area-id
  8. serial restart-delay count
  9. end

DETAILED STEPS

  Command or Action Purpose

Step 1

enable

Example:

Device> enable
Enables privileged EXEC mode.
  • Enter your password if prompted.

Step 2

configure terminal

Example:

Device# configure terminal

Enters global configuration mode.

Step 3

interface type number

Example:

Device(config)# interface serial 2/0

Specifies the interface type and number.

Step 4

ipv6 enable

Example:

Device(config-if)# ipv6 enable

Enables IPv6 processing on an interface that has not been configured with an explicit IPv6 address.

Step 5

ospfv3 multi-area multi-area-id

Example:

Device(config-if)# ospfv3 multi-area 100
Configures multiarea adjacency on the interface.
  • The multi-area-id argument identifies the OSPFv3 multiarea. The range is from 0 to 4294967295, or you can use an IP address.

Step 6

ospfv3 multi-area multi-area-id cost interface-cost

Example:

Device(config-if)# ospfv3 multi-area 100 cost 512

(Optional) Specifies the cost of sending a packet on an OSPFv3 multiarea interface. Use this command to specify the cost only if you want the cost of the multiarea interface to be different than the cost of the primary interface.

Step 7

ospfv3 process-id ipv6 area area-id

Example:

Device(config-if)# ospfv3 1 ipv6 area 0
Configures the OSPFv3 interface.
  • The process-id argument identifies the OSPF process. The range is from 1 to 65535.
  • The area-id argument identifies the OSPF area. The range is from 0 to 4294967295, or you can use an IP address.

Step 8

serial restart-delay count

Example:

Device(config-if)# serial restart-delay 0

Sets the amount of time that the router waits before trying to bring up a serial interface when it goes down. The count argument specifies the frequency (in seconds) at which that hardware is reset. The range is from 0 to 900.

Step 9

end

Example:

Device(config-if)# end

Returns to privileged EXEC mode.

Verifying OSPFv3 Multiarea Adjacency

SUMMARY STEPS

  1. enable
  2. show ospfv3 interface brief
  3. show ospfv3 multi-area
  4. show ospfv3 interface

DETAILED STEPS

  Command or Action Purpose

Step 1

enable

Example:

Device> enable
Enables privileged EXEC mode.
  • Enter your password if prompted.

Step 2

show ospfv3 interface brief

Example:

Device# show ospfv3 interface brief

Displays brief information about Open Shortest Path First version 3 (OSPFv3) interfaces.

Step 3

show ospfv3 multi-area

Example:

Device# show ospfv3 multi-area

Displays information about OSPFv3 multiarea interfaces.

Step 4

show ospfv3 interface

Example:

Device# show ospfv3 interface

Displays information about OSPFv3 interfaces.

Configuration Examples for OSPFv3 Multiarea Adjacency

Example: OSPFv3 Multiarea Adjacency Configuration


Device> enable
Device# configure terminal
Device(config)# interface serial 2/0
Device(config-if)# ipv6 enable
Device(config-if)# ospfv3 multi-area 100
Device(config-if)# ospfv3 multi-area 100 cost 512
Device(config-if)# ospfv3 1 ipv6 area 0
Device(config-if)# serial restart-delay 0
Device(config-if)# end

Example: Verifying OSPFv3 Multiarea Adjacency

Sample Output for the show ospfv3 interface brief Command

To display brief information about Open Shortest Path First version 3 (OSPFv3) interfaces, use the show ospfv3 interface brief command in privileged EXEC mode.

Device# show ospfv3 interface brief

Interface PID Area  AF   Cost  State Nbrs F/C
Se2/0     1   0    ipv6  64    P2P   1/1
MA2 1     1   100  ipv6  512   P2P   1/1
To display information about OSPFv3 multiarea interfaces, use the show ospfv3 multi-area command in privileged EXEC mode.

Device# show ospfv3 multi-area

OSPFV3_MA2 is up, line protocol is up
Primary Interface Serial2/0, Area 100
Interface ID 10
MTU is 1500 bytes
Neighbor Count is 1

To display information about OSPFv3 interfaces, use the show ospfv3 interface command in privileged EXEC mode. 


Device# show ospfv3 interface

Serial2/0 is up, line protocol is up
Link Local Address 2001:DB8:0:FFFF::1, Interface ID 10
Area 0, Process ID 1, Instance ID 0, Router ID 10.0.0.12
Network Type POINT_TO_POINT, Cost: 64
Transmit Delay is 1 sec, State POINT_TO_POINT
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
Hello due in 00:00:07
Graceful restart helper support enabled
Index 1/1/1, flood queue length 0
Next 0x0(0)/0x0(0)/0x0(0)
Last flood scan length is 1, maximum is 1
Last flood scan time is 0 msec, maximum is 0 msec
Neighbor Count is 1, Adjacent neighbor count is 1
Adjacent with neighbor 10.0.0.22
Suppress hello for 0 neighbor(s)
Multi-area interface Count is 1
OSPFV3_MA2 interface exists in area 100 Neighbor Count is 1
OSPFV3_MA2 is up, line protocol is up
Link Local Address 2001:DB8:0:FFFF::1, Interface ID 10
Area 100, Process ID 1, Instance ID 0, Router ID 10.0.0.12
Network Type POINT_TO_POINT, Cost: 512
Transmit Delay is 1 sec, State POINT_TO_POINT
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
Hello due in 00:00:08
Graceful restart helper support enabled
Index 1/1/2, flood queue length 0
Next 0x0(0)/0x0(0)/0x0(0)
Last flood scan length is 1, maximum is 1
Last flood scan time is 0 msec, maximum is 0 msec
Neighbor Count is 1, Adjacent neighbor count is 1
Adjacent with neighbor 10.0.0.22

Additional References for OSPFv3 Multiarea Adjacency

Related Documents

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Cisco IOS commands

Cisco IOS Master Command List, All Releases

IPv6 commands

Cisco IOS IPv6 Command Reference

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Feature Information for OSPFv3 Multiarea Adjacency

The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.

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