Avaya ERS 8600 series, Configuration Manual

Page: 50 / 420

New LSAs
OSPFv3 includes link LSAs and Intra-Area-Prefix LSAs.
Link LSA
Link LSA uses local-link flooding scope, not flooded beyond the associated link.
Link LSAs have three purposes:
• to provide the link-local address of the router to all other nodes on the link
• to provide the list of IPv6 prefixes associated with the link
• to allow the router to associate options bits with the network LSA for the link
Intra-Area-Prefix-LSA
The Intra-Area-Prefix-LSA carries all IPv6 prefix information. In IPv4, this information is in
router LSAs and Network LSAs.
Unknown LSA types
In OSPFv3, unknown LSA types are either stored and flooded as though understood or given
local flooding scope. Specific behavior is coded in the LS type field of the header.
Stub area
OSPFv3 retains the concept of stub areas, which minimize link-state databases and routing
table sizes.
IPv6 stub areas carry only router LSAs, network LSAs, Inter-Area-Prefix-LSAs, link LSAs, and
Intra-Area-Prefix-LSAs.
Unlike IPv4, IPv6 can store LSAs with unrecognized link state (LS) types or flood them as
though they are understood. Rules applied to the stub area prevent the excessive growth of
the link-state database. An LSA with an unrecognized link state can be flooded only if the LSA
uses area or link-local flooding scope, and the LSA U-bit is configured to 0.
IPv6 routing fundamentals
50 Configuration — IPv6 Routing November 2010