OSPF area types

[Manish Prasad]

Hi,

What is the difference between these two commands "nssa no-summary" and "stub no-summary"?

Do both these commands acts as a totally stubby area and block all the LSA type 3,4 and 5 messages ?

Thanks

Prasad

[Thotsaphon Lueangwattanaphong · Accepted solution]

Prasad,

- Stub area does not allow Type5(No ASBR).

- NSSA area does not allow Type5 but allows type7(Created by ASBR).

- No-summary keyword means InterArea routes aren't allowed(Type3,4)

HTH,

Toshi

[Edison Ortiz]

The main difference between the 2 is the function of the border router.

With a totally stub design, the border router participating in the area can't be the redistribution point of the network.

With a nssa totally stubby design, the border router participating in the area can be used as a redistribution point for external areas.

Both designs will inject a 0.0.0.0 LSA Type 3 into the area.

HTH,

__

Edison.