OSPF LSA Type Easy Note

LSA Type:

The 1-class LSA, the routing LSA, generates one per router, and the domain generates direct-attached neighbors and routed interface information (prefix,mask,metric) that do not span other regions, declaring the internal zone.

Note: The 1 class LSA contains 3 link information:

1. another Router (directly attached to WHO)

2. Stub Network (only two routers are interconnected, such as peer-to, where loopback is also considered this type of network)

3. Transit Network (two + routers connected in MA networks)

4. 
   

Class 2 Network LSA, an intra-zone declaration (with mask information), in the MA network, by the DR, if the 1-class LSA "another Router" way to represent the connection between routers, if there are N routers will have a * (n-1) bar expression entries, This is cumbersome and unnecessary, so the unity is represented by the 2 class LSA to indicate which routes are attached to this network (Attach Router-id).

Note: 1, 2 LSA, declares the intra-domain route, needs to use together.

Class 3 Abstract LSA, declares inter-domain routing, generated by the ABR, and each area of an ABR becomes an ABR of the region.

The 4 Class ASBR digest LSA is used in conjunction with the 5 class ASBR LSA, because the 5 class LSA declares the rid of the external ASBR, while the other zones cannot reach the region where the ASBR resides through the RID. 1, 2 classes cannot be passed between domains, 3 classes do not have RID, so can only rely on the Class 4 LSA service.

The 5 class ASBR LSA, combined with the 4 class LSA used, passes between domains, announcing the introduction of external routes.

This article is from the "E-Network Deep" blog, please be sure to keep this source http://jettcai.blog.51cto.com/1447637/1665741

OSPF LSA type Easy Note