Configuring OSPF for IPv6

Problem

You want to use OSPF on an IPv6 network.

Solution

The configuration for OSPFv3 is the same as for OSPFv2, the IPv4 version of OSPF, except that you use set ospf3 commands instead of set ospf commands:

[edit protocols] aviva@RouterJ# set ospf3 area 0.0.0.0 interface fe-1/0/0.0 aviva@RouterJ# set ospf3 area 0.0.0.0 interface lo0.0 passive

Discussion

JUNOS OSPFv3 configuration for IPv6 networks is basically identical to OSPFv2 configuration. You configure the protocol with set ospf3 commands instead of set ospf commands and use show ospf3 commands instead of show ospf commands to check on the OSPF status. Also, make sure to set IPv6 address on the interfaces running OSPFv3 and on the loopback interface, lo0.

This recipe shows how to configure an OSPFv3 backbone router. All backbone routers have the same basic configuration. As with OSPFv2, define which interfaces are in the area. Again, include the lo0 interface, configured as a passive interface, so that it advertises its address into OSPF.

To check that OSPF is running on the router interfaces, use the show ospf3 interface command:

aviva@RouterH> show ospf3 interface Interface State Area DR-ID BDR-ID Nbrs fe-1/0/0.0 DR 0.0.0.0 192.168.18.1 10.0.0.1 1 lo0.0 DRother 0.0.0.0 0.0.0.0 0.0.0.0 0

The output shows that OSPFv3 is running on the configured interfaces, fe-1/0/0 and lo0, and that the Fast Ethernet interface is the DR. The DR-ID and BDR-ID columns show the OSPF router ID of the DR and BDR routers.

Use the following command to see the neighbors with which the router has formed OSPFv3 adjacencies:

aviva@RouterH> show ospf3 neighbor ID Interface State Pri Dead 10.0.0.1 fe-1/0/0.0 Full 128 36 Neighbor-address fe80::205:85ff:fec4:72f4

You see one adjacency, with the router ID 10.0.0.1, which is the neighbor via interface fe-1/0/0. As with OSPFv2, Full in the State column indicates that the OSPFv3 adjacency is up and running. The neighbor has a default priority of 128, the same default as OSPFv2, which is used to elect the DR.

To see the OSPF routing table on the router, use the show ospf3 route command:

aviva@RouterH> show ospf3 route Prefix Path Route NH Metric type type type 10.0.0.1 Intra Router IP 1 NH-interface fe-1/0/0.0, NH-addr fe80::205:85ff:fec4:72f4 192.168.18.1;0.0.0.3 Intra Transit IP 1 NH-interface fe-1/0/0.0 9009:3::/64 Intra Network IP 1 NH-interface fe-1/0/0.0

The prefix column shows the routes to the other Area 0 router. One difference in the output for OSPFv3 is that the loopback address, 192.168.18.1, shows up as type TRansit instead of as Network to indicate that the loopback address is not on a real OSPF network. Route 192.168.18.1:0.0.0.3 actually represents a route to the pseudonode corresponding to the fe-1/0/0 link. (In OSPFv3, a LAN link is called a transit link.) Any multiaccess link, such as a LAN or an NBMA link, is represented by a fake node, or pseudonode, in the IGP. This route is used for debugging and is not installed in the forwarding table.

The OSPFv3 link-state database contains more information than for OSPFv2:

aviva@RouterH> show ospf3 database OSPF3 link state database, area 0.0.0.0 Type ID Adv Rtr Seq Age Cksum Len Router 0.0.0.0 10.0.0.1 0x80000422 933 0x3338 40 Router *0.0.0.0 192.168.18.1 0x80000013 327 0x1fee 40 Router 0.0.0.0 192.168.19.1 0x80000012 3399 0x98e4 56 Network *0.0.0.3 192.168.18.1 0x80000003 27 0x31ee 32 Network 0.0.0.1 192.168.19.1 0x8000000e 3399 0x4352 36 IntraArPfx *0.0.0.4 192.168.18.1 0x80000002 932 0x2602 44 IntraArPfx 0.0.0.2 192.168.19.1 0x8000000d 3399 0xe937 44 OSPF3 Link-Local link state database, interface fe-1/0/0.0 Type ID Adv Rtr Seq Age Cksum Len Link 0.0.0.4 10.0.0.1 0x80000001 933 0xd6af 56 Link *0.0.0.3 192.168.18.1 0x80000005 627 0x3f76 56

In addition to listing the entries in this area, Area 0.0.0.0, the second part of the output shows the entries in the link-local, link-state database for this interface. These are the database entries learned over the specific OSPFv3 interface and they are visible only by nodes that are directly on this link.

See Also

Recipes 7.6 and 12.1