Chapter 27: Ospfv3 Commands - Extreme Networks ExtremeWare XOS Command Reference Manual

27 OSPFv3 Commands
This chapter describes commands used for the IPv6 interior gateway protocol OSPFv3.
Open Shortest Path First (OSPFv3) is a link-state protocol that distributes routing information between
routers belonging to a single IP domain, also known as an autonomous system (AS). In a link-state
routing protocol, each router maintains a database describing the topology of the autonomous system.
Each participating router in an area has an identical database maintained from the perspective of that
router.
OSPFv3 supports IPv6, and uses commands only slightly modified from that used to support IPv4.
OSPFv3 has retained the use of the four-byte, dotted decimal numbers for router IDs, LSA IDs, and area
IDs.
From the link-state database (LSDB), each router constructs a tree of shortest paths, using itself as the
root. The shortest path tree provides the route to each destination in the autonomous system. When
several equal-cost routes to a destination exist, traffic can distributed among them. The cost of a route is
described by a single metric.
OSPFv3 allows parts of a networks to be grouped together into areas. The topology within an area is
hidden from the rest of the autonomous system. Hiding this information enables a significant reduction
in link-state advertisement (LSA) traffic, and reduces the computations needed to maintain the LSDB.
Routing within the area is determined only by the topology of the area.
The three types of routers defined by OSPFv3 are as follows:
Internal Router (IR)—An internal router has all of its interfaces within the same area.
●
Area Border Router (ABR)—An ABR has interfaces belonging to two or more areas. It is responsible
●
for exchanging summary advertisements with other OSPFv3 routers.
Autonomous System Border Router (ASBR)—An ASBR acts as a gateway between OSPFv3 and
●
other routing protocols, or other autonomous systems.
Each switch that is configured to run OSPFv3 must have a unique router ID. It is recommended
especially that you manually set the router ID of the switches participating in OSPFv3, instead of
having the switch automatically choose its router ID based on the highest interface IPv4 address, since
your router may not have an IPv4 address. Not performing this configuration in larger, dynamic
environments could result in an older LSDB remaining in use.
NOTE
Do not set the router ID to 0.0.0.0.
Licensing
To use OSPFv3, you must have a Core license installed on your switch. The BlackDiamond 10K ships
with a Core, or Advanced Core license. Other platforms can be upgraded to a Core license. See the
section "Software Licensing" on page 33
ExtremeWare XOS 11.3 Command Reference
for more information about licensing.
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