An IS-IS level 1-only router is configured within a larger multilevel hierarchy.Which OSPF area type resembles the routing information in the L1 router’s table?
A.
OSPF default area
B.
OSPF stub area
C.
OSPF NSSA
D.
OSPF NSSA with no summaries
Which OSPF area type resembles the routing information in the L1 router’s table?
An IS-IS level 1-only router is configured within a larger multilevel hierarchy.Which OSPF area type resembles the routing information in the L1 router’s table?
I ‘m not sure why it isn’t B…
Muy simple, recuerda que los ruteadores del level-1 reciben rutas internas de sus areas, una ruta default publicado por su ABR para alcanzar a sus rutas interareas y ademas es posible que se inyecten rutas externas L1 usando policy.
en el caso de OSPF area stub no puede ser por que este aun recibe rutas interareas, NSSA es un area stub pero que permite que se generen rutas externas en su area de modo que lo mas cercano a area L1 en ospf es no-so-stubby-area NSSA = D
is-is level-1 device will not allow the redistribution of its directly connected interface. it cannot be a nssa area where redistribution is possible.
Answer: B. OSPF stub area
It is D, NSSA no summaries. There are only level 1 LSA + Default generated in L1 = OSPF LSA Type 1 + no summaries. NSSA allows externals, so does L1
http://www.juniper.net/techpubs/software/junos-security/junos-security10.1/junos-security-swconfig-interfaces-and-routing/protocols-is-is-overview-section.html#protocols-is-is-overview-section
IS-IS does not force the network to use a hierarchical physical topology. Instead, a single AS can be divided into two types of areas: Level 1 areas and Level 2 areas.
A Level 1 area is similar to an OSPF stub area, and a Level 2 area interconnects all Level 1 areas. The router and its interfaces reside within one area, and Level 2 routers share link-state information. No IS-IS area functions strictly as a backbone.
answer must be B
http://www.juniper.net/techpubs/software/junos-security/junos-security96/junos-security-swconfig-interfaces-and-routing/protocols-is-is-overview-section.html
it is stub.
A Level 1 area is similar to an OSPF stub area, and a Level 2 area interconnects all Level 1 areas
The most correct answer available in multiple choice is D (OSPF NSSA with no summaries)
Actually correct answer should be Totally stubby area per link below, but that option is not available in the multiple choice.
http://www.juniper.net/techpubs/en_US/junos12.2/topics/example/isis-multi-level.html
Example: Configuring Multi-Level IS-IS
Overview
Like OSPF, the IS-IS protocol supports the partitioning of a routing domain into multiple areas with levels that control inter-area flooding. The use of multiple levels improves protocol scalability, as level 2 (backbone) link-state protocol data units (LSPs) are normally not flooded into a level 1 area.
An IS-IS level 2 area is analogous to the OSPF backbone area (0), while a level 1 area operates much like an OSPF totally stubby area, in that a default route is normally used to reach both inter-level and AS external routes.
Here is how you configure a totally stubby area
http://www.juniper.net/techpubs/en_US/junos12.2/topics/example/ospf-stub-area-configuring.html
(Optional) On the ABR, restrict summary LSAs from entering the area. This step converts the stub area into a totally stubby area.
[edit]
user@host# set protocols ospf area 0.0.0.7 stub no-summaries