An administrator has an AOS-CX switch configured with:
router ospf 1
area 0
area 1 stub no-summary
It is the only ABR for area 1. The switch has the appropriate adjacencies to routing switches in areas 0 and 1. The current routes in each area are:
Area 0: 5 routes (LSA Type 1 and 2)
Area 1: 10 routes (LSA Type 1 and 2)
External routes: 2 (LSA Type 5)
Based on the above configuration, how many OSPF routes will routing switches see in Area 1?
When an OSPF area is configured as a totally stub area using the 'no-summary' keyword, it will block summary routes from other areas and external routes (LSA Type 5s). Therefore, only intra-area routes (LSA Types 1 and 2) and a default route will remain. In this case, Area 1 has 10 intra-area routes plus one default route, resulting in a total of 11 OSPF routes.
default route + 10 routes =11
the correct Answer is B
No its C
How come it's B? The area itself already has 10 routes.
Its a completely stub area so no type 5 lsa will come in, only the local routes and the default so 11 is the correct answer for sure.
Option c : Totally stub area = intra area routes (local route) + default route
Page 397 Study Guide: The no- summary option transforms a stub area to a totally stub area – it suppresses all external route advertisements as normal for a stub area. It also prevents the ABR from generating non- aggregated Inter- Area (IA) summary routes for this area. [Aruba Networks]
Its a completely stub area so no type 5 lsa will come in, only the local routes and the default so 11 is the correct answer for sure.