LSA Types
| Type 1 – Router Tells the other routers about directly connected links |
| Type 2 – Network When routers are in a multiaccess network (think ethernet connection with DR election), the lead router, the “designated router” or DR tells other routers about the multiaccess network connections. |
| Type 3 – Summary (Tricky name not actually summarized routes) When LSA Type 1 & 2 are re-advertised into another area, they are converted to type 3 “summary” routes. These type 3’s would also be re-advertised into any areas that they didn’t source from. |
| Type 4 – ASBR Summary This one is a bit confusing, it advertises the route to an ASBR router, it is only needed when the ASBR isn’t directly connected to a specific area. |
| Type 5 – Autonomous system external An ASBR tells other routers about a router redistributed from outside OSPF, gets re-advertised to all (normal) areas. |
| Type 6 – Multicast |
| Type 7 – NSSA In an NSSA, this type of LSA gets generated instead of a type 5 route, then gets converted to a type 5 LSA when going into another area. |
| Type 8 – External attribute for BGP |
Area Types
Backbone area (area 0)
Standard area
Stub area
Totally stubby area
Not-so-stubby area (NSSA)
In progress… to be continued