GNS3 Topology: OSPF AREA TYPEs and LSA TYPEs

PART 1



PART 2





 I think I should begin this topic with OSPF router types. There are 4 types of routers in an OSPF. These are

a- Internal Router: This is a router which has all interfaces connected to same area.

b- Backbone Router: This is a router which has at least one interface connected to area 0.

c- ABR (Area Border Router): this is a router which has interfaces connected to multiple areas.

d- ASBR (autonomous system boundary router): this is a router which has at least one interface connected to an external internetwork.

One router can have multiple roles.


Although we saw only 6 types of LSA, there are 11 types of LSA 

LSA Type     Description

   1                 Router LSA
   2                 Network LSA
3 and 4          Summary LSAs
  5                 AS external LSA
  6                 Multicast OSPF LSA
  7                 Defined for not-so-stubby areas (NSSAs)
  8                 External attributes LSA for Border Gateway Protocol (BGP)
9, 10, 11       Opaque LSAs