In this post we will talk bout the differences between OSPFv2 and OSPFv3 LSA’s
An LSA (Link state advertisement) is a packet-type used by OSPF to communicate information about to network to its neighbors. OSPFv2 uses a number of different LSA’s as listed below.
LSA Type 1 – Router LSA – Generated by all routers in OSPF and flooded within a single area. Gives information about local links and subsets of that router. Also contain the routes RID.
LSA Type 2 – Network LSA – Generated by the DR on a multi-point network type. List all attachments to the DR.
LSA Type 3 – Network Summary LSA – Generated by the ABR and send to attached areas containing information about destination prefixes for a area.
LSA Type 4 – ASBR Summary LSA – Generated by that ABR containing a route to the ASBR so other routes have a way of the OSPF domain.
LSA Type 5 – External LSA – Generated by the ASBR containing routes outside the OSPF Domain. An example of this is routes redistributed from another routing protocol.
LSA Type 6 – Group Membership LSA- used for MOSPF
LSA Type 7 – NSSA External – Smiler to Type 5 but is generated by a ASBR in a Not-so-stubby area type.
LSA Type 8 – External-Attributes-LSA – Uses to carry BGP ASN
LSA’s Type 9,10 and 11 – Opaque LSA.
LSA Type 9 is ues for OSPF graceful restart and LSA Type 10 is ues for MPLS TE
Like OSPFv2, OSPFv3 Carries IPv4 prefixes but also caries IPv6. Now we will have a look at OSPFv3 LSA (RFC 5340)
LSA Type 1 – Router LSA – Generate by all OSPF router giving information about itself. Flooded within an area. (0×2001)
LSA Type 2 – Network LSA – Generated by the DR on a multi-point network type. List all attachments to the DR. (0×2002)
LSA Type 3 – Inter-area-prefix LSA – Generated by a ABR and contains information on prefixes form other areas. (0×2003)
LSA Type 4 – Inter-area-router LSA – Generated by an ABR providing information of ASBR. (0×2004)
LSA Type 5 – As-External LSA – Same as OSPFv2 Generated by the ASBR containing routes outside the OSPF Domain. An example of this is routes redistributed from another routing protocol. (0×4005)
LSA- Type 6 – Deprecated
LSA Type 7 – Type-7 LSA – As above Generated by ASBR’s within a NSSA. (0×2007)
LSA Type 8 -Link – Generated by all OSPF routers. Carries information about links and assisted address. Flooded between links. (0×0008)
LSA Type 9 – Intra-area-prefix – Generated by OSPF routers in an area providing information about links and address associated. (0×2009)
Along with this there is also a flooding scope including with the OSPF LSA packet in OSPFv3. This is as follows
S2 S1 Flooding Scope
0 0 Link Local
0 1 Area
1 0 Autonomous System
1 1 Reserved