OSPF LSA Types
LSA:
====
1)router LSA How many routers (generated by all routers)
2)Network LSA Who is DR?
3) Summary LSA-generated by ABR, Who is other area network? (inter area routes)
4) ASBR Summary LSA - Generated by ABR - contains routes to ASBR
5) External LSA All external routes
6) Multicast LSA- used for multicast applications.
7) NSSA External LSA
| NBMA | BROADCAST | P2P | MULIPOINT BROADCAST | MULTIPOINT NON BROADCAST | |
| DR/BDR==> | YES | YES | NO | NO | NO |
| Neighbor==> | NO | YES | YES | YES | NO |
Stub Area :-
=========
REASON:-if router has less memory then it can impact the performance,reduce CPU
LSA 1,2,3 and a default route is injected at LSA type 3
{TO BLOCK =type 4(ASBR), Type5(External routes) }
Totally Stubby Area :-
===================
REASON:-if router has less memory then it can impact the performance,reduce CPU
LSA 1,2, is allowed and a default route is injected at LSA type 3
with a default route as a type 3 LSA
(TO BLOCK =type 3,4,5=inter area,ASBR,External routes)
Here you can see the NP bit. This bit position has two roles:
N-bit: this one is used in hello packets for OSPF NSSA routers. When the N-bit is not supported, the routers won’t become neighbors.
P-bit: this one is only used in the NSSA external LSA header.
Since the N and P bit are never used at the same time, this bit position can be used for both roles.
Not So Stubby Area (NSSA) :-
=========================
- No Type 7/5 translation means bit P = 0.
- Type 7/5 translation means bit P = 1.
REASON:-
1)if router has less memory then it can impact the performance,reduce CPU
2)My company has two AREAS(AREA0--AREA1), where Area1 is in STUB.
Now your company wants to communicate with our company.
so in this i can put AREA1 in NSSA so it will not learn your routes(external routes) only area0 will learn.
NOTE:- If you dont want LSA-7 to learn then give below command
router ospf 1 Area 1 nssa no-redistribution
LSA 1,2,3,7,default route is injected at LSA type 7 only if below command is issued
area 10 nssa default-information-originate
-(TO BLOCK LSA 4,5=ASBR,EXTERNAL)
TOTALLY NSSA:-
=================
-LSA 1,2,7 is allowed and default route is injected at LSA type3
++Interarea route, ASBR and External routes are blocked.
CASINO HOTEL AND CASINO $25K CASINO $25K GAMES - Mapy
Hotel Casino and Resort Atlantic City (MapYRO) is 제주 출장안마 a AAA 포천 출장마사지 Four-Diamond accredited luxury hotel and 태백 출장샵 casino located in New 동해 출장샵 London, 경상남도 출장안마 NJ.