- In enterprise networks, the application of IPv6 technology is becoming more and more popular. The IETF organization has developed a routing protocol OSPFv3 for IPv6 networks .
OSPFv3
- ff02::5 is an IPv6 multicast address reserved for the OSPFv3 routing protocol .
- The next hop address of routing entries in OSPFv3 is the link local address.
- OSPFv3 is an OSPF protocol running on IPv6 networks . Routers running OSPFv3 use the link-local unicast address of the physical interface as the source address to send OSPF messages. Routers on the same link learn from each other the link local addresses of other routers connected to them , and use these addresses as next hop information during packet forwarding . The scenario of virtual links is not within the scope of this course . .
- The multicast address ff02::5 is used in IPv6 to represent AllSPFRouters , while the multicast address 224.0.0.5 is used in OSPFv2 . It should be noted that OSPFv3 and OSPFv2 versions are incompatible with each other .
DR&BDR
- Router ID must be configured manually in OSPFv3 .
- The process of OSPFv3 electing DR and BDR in NBMA and broadcast networks is similar to OSPFv2 .
- Router ID is also used to identify routers in OSPFv3 . Different from the Router ID of OSPFv2 , the Router ID of OSPFv3 must be manually configured; if the Router ID is not manually configured , OSPFv3 will not operate properly. The process of OSPFv3 electing DR and BDR in broadcast networks and NBMA networks is similar to OSPFv2 .
- IPv6 uses the multicast address FF02::6 to represent AllDRouters , while OSPFv2 uses the multicast address 224.0.0.6 .
Run on a link
- OSPFv2 operates based on network segments , and the implementation of OSPFv3 is based on links.
- OSPFv3 is based on links rather than network segments. When configuring OSPFv3, you do not need to consider whether the router's interfaces are configured on the same network segment. As long as the router's interfaces are connected to the same link, you can directly establish contact without configuring an IPv6 global address. This change affects the reception of OSPFv3 protocol messages, the contents of Hello messages, and the contents of network LSAs.
OSPFv3 certification
- The OSPFv3 protocol itself does not provide authentication functions. Instead, it uses the security mechanism provided by IPv6 to ensure the legitimacy of OSPFv3 messages.
- OSPFv3 directly uses IPv6 extension headers ( AH and ESP ) to implement authentication and security processing, and OSPFv3 itself is no longer required to complete authentication.
OSPFv3 configuration
[RTA]ipv6
[RTA]ospfv3
[RTA-ospfv3-1]router-id 1.1.1.1
[RTA-GigabitEthernet0/0/0]ipv6 enable
[RTA-GigabitEthernet0/0/0]ipv6 address fe80::1 link-local
[RTA-GigabitEthernet0/0/0]ospfv3 1 area 0.0.0.0
[RTA-LoopBack0]ipv6 enable
[RTA-LoopBack0]ipv6 address 2001:1::1/64
[RTA-LoopBack0]ospfv3 1 area 0.0.0.0
- The ipv6 command is used to enable the IPv6 function of the router. To run the OSPFv3 protocol on the router , the IPv6 function must first be enabled .
- The ospfv3 [ process-id ] command is used to create and run the OSPFv3 process. The process-id value range is 1 ~ 65535 . If you do not specify a process number, process number 1 is used by default .
- The router-id router-id command is used to set the ID number of the router running the OSPFv3 protocol .
- The ipv6 enable command is used to enable IPv6 on the router interface so that the interface can receive and forward IPv6 packets. The IPv6 function of the interface is disabled by default. The ipv6 address < link local address > link-local command is used to manually configure the link local address for the interface.
- The ospfv3 process-id area area-id command is used to enable the OSPFv3 process on the interface and specify the area to which it belongs.
- In this example , the loopback interface of the router RTA and the GigabitEthernet0/0/0 interface both enable the OSPFv3 process and belong to area 0 .
Configuration verification
[RTA]display ospfv3
Routing Process "OSPFv3 (1)" with ID 1.1.1.1
Route Tag: 0
Multi-VPN-Instance is not enabled
SPF Intelligent Timer[millisecs] Max: 10000, Start: 500, Hold: 2000
LSA Intelligent Timer[millisecs] Max: 5000, Start: 500, Hold: 1000
LSA Arrival interval 1000 millisecs
Default ASE parameters: Metric: 1 Tag: 1 Type: 2
Number of AS-External LSA 0. AS-External LSA's Checksum Sum 0x0000
Number of AS-Scoped Unknown LSA 0. AS-Scoped Unknown LSA's Checksum Sum 0x0000
Number of FULL neighbors 1
Number of Exchange and Loading neighbors 0
……
- After completing the OSPFv3 configuration on the neighbor router , run the display ospfv3 command to verify the OSPFv3 configuration and related parameters. From the displayed information, you can see that the running OSPFv3 process is 1 , the Router ID is 1.1.1.1 , and the Number of FULL neighbors value is 1 .
Chapter summary
Q: What are the parameters used by OSPFv3 to uniquely identify a router ?
Answer: Router ID is used to uniquely identify a router running OSPFv3 protocol.