Exam 300-410 topic 1 question 240 discussion

B is the right answer, lab it.

For those that say C, when you filter OUT of Area 20 on R2, to which areas are you preventing the updates to enter? That would be Areas 0, 10 which is not what's required here. The thing is on which Router are you filtering. OUT direction would work if the filtering was being done on R5. The correct answer is B, you are filtering INto Area 20 so that updates from Area 0, 5 and Area 10 are not allowed in 20.

in direction of area 20 not in direction of router 2, it is C

filter-list is applied on the area border router area 0 ABR: in this case R2 our option is filter-list ourt of area 0 or filter-list into area 20 We should filter "in" area 20, so it shows up still in Area 10.

After the respective route filtering configuration is applied on the ABR, area 5 routes are not visible on any of the areas. R1 is ABR or Area 5, the issue is here, therefore D the given answer is correct.

Route Filtering: "in" direction: This would filter routes as they are received by the ABR from another area. "out" direction: This filters routes as they are advertised out of the ABR to other areas.

In = Into the area

B is correct

I cannot understand why you should choose B, the area 20 is the area between R5 that is the router connected to the business parter and our ospf domain... If I need to filter routes from area 5 and all the other areas needs this information is easy to understand that i need to filter these network in outbound direction to R5. I cannot filter in inbound the networks that I received from area 0 in router 2. B is for sure not right, C it is.

b is the right for me, doesnt make sense to me to put it in the out direction.

Question states that ALL other areas need to have area 5 routes *(including area 10). For this reason, placing the filter outward "OUT" toward area 20 would satisfy the requirement.

"in" direction means it not show up Area 20, and not show up business partner (not get propagated to R2's LSDB) which is not requirement. out direction it shows up Area 20 and not in Business Partner. Answer = B

I have labbed in CML and think it is B. The only downside to this answer is that it prevents area 20 from learning the prefix.

B is correct answer Logic is to pay attention to the option in which area it has asked to apply a filter. If the option was for Area 0 then it should be in the OUT direction i.e. routes going out of Area 0 into another area. The question has asked to apply a filter in Area 20 which can satisfy condition - inter area routes on the area 5 ABR should be protected from getting into the business partner network, all other areas (area 00 and Area 10) should receive the area 5 internal routes R5 is the only router in Area 20 and Area 20 needs to be blocked from receiving routes hence it should be "IN" Direction i.e routes should be blocked entering area 20 https://community.cisco.com/t5/networking-knowledge-base/using-area-lt-gt-filter-llist-command-in-ospf/ta-p/3118832

C is the correct answer I don’t know how tamangao labbed it.

"in" direction to R2 will block area 5 propagating to area 10. So, it's C, "out" R2

Right answer is B The question is a bit misleading by saying every area must learn about the route I believe R2 belongs to us but R5 belongs to the business partner, Area 20 is the area between us and the business partner that we both use to share routes and this is where we control what routes we share with them, by filtering what goes into area 20 on R2 A is just silly trying to filter a route that originates for Area 5 from coming into Area 5 D is the exact thing the Engineer has done which is causing the problem - prevent R1 from advertising the route from area 5 into area 0 which means R2 does not know about it in area 0 to advertise it further to area 10 where it is also needed internally C is telling R2 not advertise the route from area 20 to any other areas (configured on R2), however, area 20 would need to learn about the route from area 0 first before it can decide whether or not to advertise it out to another area. Best place to apply option C would be on R5 but as mentioned above, I do not believe it is under our jurisdiction