The purpose of OSPF NSSA and NSSA totally stub
In OSPF there are many area types:
Stub area : will block external routes LSA type 5, but allow inter area routes LSA type 3 and 4 and injects default route
Totally Stub area: Block External as well as Inter area routes, and inject default route.
Well if I understand the purpose of creating the above areas is kind of reducing the size of the routing table. if that's the case why not just use the Totally Stub area and that will do the job ? I mean without worrying about creating the stub area .
OSPF also has NSSA and NSSA totally stub, when do we need these areas ? I know that NSSA when receiving the redistributed external routes it will mark them as Type 7, then the ABR will convert them to type 5 LSA, but what purpose it serves if it does not reduce the size of the routing table ? Type 7 or Type5 will not reduce the size if I understand..
Thank you
Stub area : will block external routes LSA type 5, but allow inter area routes LSA type 3 and 4 and injects default route
Totally Stub area: Block External as well as Inter area routes, and inject default route.
Well if I understand the purpose of creating the above areas is kind of reducing the size of the routing table. if that's the case why not just use the Totally Stub area and that will do the job ? I mean without worrying about creating the stub area .
OSPF also has NSSA and NSSA totally stub, when do we need these areas ? I know that NSSA when receiving the redistributed external routes it will mark them as Type 7, then the ABR will convert them to type 5 LSA, but what purpose it serves if it does not reduce the size of the routing table ? Type 7 or Type5 will not reduce the size if I understand..
Thank you
SOLUTION
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
SOLUTION
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
ASKER
This is part of Learning only....
I just wanted to know when should we resort to NSSA or NSSA Totally Stubby.
Knowing that the normal Totally Stubby area can inject the default route and block LSA 3,4,5,7
Regarding "default-information originate", it does not filter out any LSA
if you create it in Router1, I believe other routers ,(I am not sure if they have to be in the same segment and/or same area ) will have a default route created in their routing table.
I just wanted to know when should we resort to NSSA or NSSA Totally Stubby.
Knowing that the normal Totally Stubby area can inject the default route and block LSA 3,4,5,7
Regarding "default-information originate", it does not filter out any LSA
if you create it in Router1, I believe other routers ,(I am not sure if they have to be in the same segment and/or same area ) will have a default route created in their routing table.
ASKER CERTIFIED SOLUTION
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
ASKER
Thanks
ASKER