IPv6 Configuration Guide K/KA/KB.15.15

Overview of OSPFv3
DetailFactor
K.15.01Minimum software version
OSPFv3 applications only; runs independent of the OSPFv2
protocol used for IPv4 OSPFv2 applications.
Application
Concurrent OSPFv2 and OSPFv3 operation supported on all
VLAN interfaces configured on the routing switch.
Concurrent IPv4/IPv6 operation
Beginning with software version K.15.01, the routing switches support concurrent operation of
both OSPFv2 (for IPv4) and OSPFv3 (for IPv6). The two versions of the OSPFv3 protocol operate
independently of each other. (For information on OSPFv2 for IPv4 operation, see the latest Multicast
and Routing Guide for your routing switch.)
OSPFv3 is a link-state routing protocol applied to IPv6 routers grouped into OSPFv3 areas identified
by the IPv6 routing configuration on each routing switch. Each OSPFv3 area includes one or more
networks. OSPFv3 routers use hello packets and LSAs to maintain OSPFv3 operation across networks
within an area and between areas within an OSPFv3 domain.
Hello packets
OSPFv3 uses hello packets to initiate and preserve relationships between neighboring routers on
the same VLAN interface. OSPFv3 automatically transmits hello packets that are configurable for
transmission interval (to indicate a link that has become unavailable).
Link-state advertisements (LSAs)
OSPFv3 uses LSAs transmitted by each router to update neighboring routers regarding its interfaces
and the routes available through those interfaces. Each routing switch in an area also maintains
an LSDB that describes the area topology. (All routers in a given OSPFv3 area have identical
LSDBs, and each router uses the LSDB to build its own shortest-path tree.) The routing switches used
to connect areas to each other flood inter-area-prefix-LSAs, inter-area-router-LSAs, and
AS-external-LSAs to neighboring OSPFv3 areas to update them regarding available routes. Through
this means, each OSPFv3 router determines the shortest path between itself and a desired destination
router in the same OSPFv3 domain (AS). Routed traffic in an OSPFv3 AS is classified as one of
the following:
• Intra-area traffic
• Inter-area traffic
• External traffic
The routing switches support the LSAs listed in the following table. For more information, see RFCs
and 3101 (for Type-7-LSA).
Table 17 OSPFv3 LSA types
Flood scopeUseDescriptionLSA type
AreaDescribes the state of each active interface on a router for a
given area. (Excludes loopback interfaces and interfaces that
have not achieved full adjacency.)
Router-LSA0x2001
AreaDescribes the OSPFv3 routers in a given network.Network-LSA0x2002
AreaDescribes the route to a prefix in another OSPFv3 area of the
same AS. Propagated through backbone area to other areas.
Inter-area-prefix-LSA0x2003
248 OSPFv3 Routing