By using the show ip ospf database we can look at the LSDB and we can see the type 1 router LSAs, type 2 network LSAs and the type 3 summary LSAs here.
Which LSA type is used to summarize routes from one OSPF area to another?
Type 3 LSAs are used whenever a router is placed between OSPF areas. It summarizes routes as router information moves across areas.
Who will generate Type-4 LSA?
This type-4 LSA is generated by an ABR, providing information to reach an ASBR. The LSA itself includes the router ID of the ASBR, the advertising router ID (which is the ABR) and a network mask of all 0s.
Which type of router would generate a type 2 LSA?
LSA Type 2 – OSPF Network LSA LSA Type 2 (Network LSA) packets are generated by the Designated Router (DR) to describe all routers connected to its segment directly. LSA Type 2 packets are flooded between neighbors in the same area of origin and remain within that area.
How many LSA are in OSPF?
We also saw the most common LSA packets found in OSPF networks. In this article we’ll be diving deeper to analyse all eleven OSPF LSA Types using network network diagrams and examples to help understand when each LSA type is used and how they keep the OSPF network updated.
Why is type 4 LSA needed?
So, a type-4 asbr-summary LSA is needed to help make the ASBR reachable and, by extension make the associated type-5 prefix valid. The type-4 acts like a glue record, and uses the ABRs well known RID as a care-of address for the ASBR and it’s advertised prefixes.
What is Type 7 LSA OSPF?
LSA Type 7: OSPF Not So Stubby Area (NSSA) External LSA. LSA Type 8: OSPF External Attributes LSA (OSPFv2) / Link Local LSA (OSPFv3) LSA Type 9: OSPF Link Scope Opaque (OSPFv2) / Intra Area Prefix LSA (OSPFv3) LSA Type 11:OSPF AS (Autonomous System) Scope Opaque LSA.
Why is LSA type 2 needed?
Put simply, yes, the routers could use type 1 LSA’s and detail every router’s links to all other routers, but this is inefficient and will introduce unnecessary bloat into the OSPF LSDB. To mitigate this, the Type 2 (network) LSA is used to represent the broadcast subnet.
What are the different types of OSPF LSA?
Type 2 is the network LSA. This is advertised by the DR in an OSPF network and describes all of the neighbors in the area. This includes the common IP prefix that they work on as well. Also, like the type 1 LSA, these advertisements stay within the area.
What does type 1 mean in router LSA?
Type 1 is commonly referred to as a Router LSA. This type of LSA describes all of the directly connected prefixes and devices to a router. This includes things like virtual-links as well. The final thing to remember on this type is that it always stays within the area that the router belongs to.
How is OSPF used in the routing table?
OSPF LSA Types. OSPF is a commonly used IGP used in a wide range of enterprise environments. It uses its algorithm to determine the shortest path to the destination network address. This algorithm is based on the overall cost of a path to the destination.
What do R3 and R4 need to know about OSPF?
R3 and R4 also need to know about the networks in Area 2. R2 is going to create a Type 3 summary LSA and flood it into area 0. This LSA will flood into all the other areas of our OSPF network. This way all the routers in other areas will know about the prefixes from other areas.