NSSA versus Totally stubby NSSA

[mangesh kamble]

Hello Everyone,

Would request for your inputs over this topic.... Design perspective which to be preferred where and when ?

Thanks.

[Jeremy Filliben]

Mangesh,

My assumption is you need external routing sources, hence the NSSA decision. "Totally" NSSA is scales better due to the reduction in LSAs and routing prefixes. The drawback is that you will have less optimal routing with regards to inter-area prefixes (both internal and external). If that is acceptable, pick Totally NSSA. If optimal inter-area routing is required, choose NSSA.

A use case for Totally NSSA is when the choice of an ABR is unimportant, such as in a high-bandwidth/low-latency campus environment. NSSA would be more appropriate in a WAN topology where the ABRs are geographically dispersed and some resource are closer to one ABR or the other.

I hope this helps,

Jeremy

www.jeremyfilliben.com