OSPFv3 is a revised version of OSPFv2 to support the IPv6 address family. Refer to Open Shortest Path First (OSPF) Protocol for a discussion on the basic concepts, which remain the same between the two versions.
OSPFv3 has changed the formatting in some of the packets and LSAs either as a necessity to support IPv6 or to improve the protocol behavior based on OSPFv2 experience. Most notably, v3 defines a new LSA, called intra-area prefix LSA to separate out the advertisement of stub networks attached to a router from the router LSA. It is a clear separation of node topology from prefix reachability and lends itself well to an optimized SPF computation.
Configuring OSPFv3 involves the following tasks:
ospf6daemons, as described in Configuring FRRouting then start the FRRouting service:
Enabling OSPFv3 and map interfaces to areas:
Defining (custom) OSPFv3 parameters on the interfaces, such as:
- Network type (such as point-to-point, broadcast)
- Timer tuning (for example, hello interval)
The OSPFv3 configuration is saved in
Unlike OSPFv2, OSPFv3 intrinsically supports unnumbered interfaces. Forwarding to the next hop router is done entirely using IPv6 link local addresses. Therefore, you are not required to configure any global IPv6 address to interfaces between routers.
Configure the OSPFv3 Area
Different areas can be used to control routing. You can:
- Limit an OSPFv3 area from reaching another area
- Manage the size of the routing table by creating a summary route for all the routes in a particular address range.
The following example command removes the
3:3::/64 route from the routing table. Without a route in the table, any destinations in that network are not reachable.
The following example command creates a summary route for all the routes in the range 2001::/64:
You can also configure the cost for a summary route, which is used to determine the shortest paths to the destination. For example:
The value for cost must be between 0 and 16777215.
Configure the OSPFv3 Distance
Cumulus Linux provides several commands to change the administrative distance for OSPF routes.
This example command sets the distance for an entire group of routes, rather than a specific route.
This example command changes the OSPF administrative distance to 150 for internal routes and 220 for external routes:
This example command changes the OSPF administrative distance to 150 for internal routes:
This example command changes the OSPF administrative distance to 220 for external routes:
This example command changes the OSPF administrative distance to 150 for internal routes to a subnet or network inside the same area as the router:
This example command changes the OSPF administrative distance to 150 for internal routes to a subnet in an area of which the router is not a part:
Configure OSPFv3 Interfaces
You can configure an interface, a bond interface, or a VLAN with an advertise prefix list.
The following example command configures interface swp3s1 with the IPv6 OSPF6 advertise prefix-list 192.168.0.0/24:
You can also configure the cost for a particular interface, bond interface, or VLAN.
The following example command configures the cost for the bond interface swp2.
See Debugging OSPF for OSPFv2 for the troubleshooting discussion. The equivalent commands are:
Another helpful command is
net show ospf6 spf tree. It dumps the node topology as computed by SPF to help visualize the network view.