300-410 Exam QuestionsBrowse all questions from this exam

300-410 Exam - Question 240


Refer to the exhibit. A network engineer applied a filter for ISA traffic on OSPFv3 inter area routes on the area 5 ABR to protect advertising the internal routes of area 5 to the business partner network. All other areas should receive the area 5 internal routes. After the respective route filtering configuration is applied on the

ABR, area 5 routes are not visible on any of the areas. How must the filter list be applied on the ABR to resolve this issue?

Show Answer
Correct Answer: BD

The filter list must be applied in the 'in' direction for Area 20 on router R2. This way, the ABR (R2) prevents the internal routes of Area 5 from being advertised into Area 20 while still ensuring that other areas, such as Area 0 and Area 10, receive the Area 5 routes. Applying the filter in the 'out' direction for Area 5 on R1 would stop Area 5 routes from propagating to all connected areas, including Area 0, which is not the intended effect. Filtering 'in' on Area 20 ensures Area 5 routes are blocked from entering the business partner network without affecting other areas.

Discussion

17 comments
Sign in to comment
tamangaoOption: B
Nov 14, 2022

B is the right answer, lab it.

bryaberson
Sep 26, 2023

R5 is not an ABR. Question states the conf must be applied to the ABR which is R2. Answer is C

asansOption: B
Dec 23, 2023

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.

inteldarvidOption: B
Jul 15, 2023

team sorry, my answer before is wrong the answer corret is B. is in for area 20

Juraj22
Jul 17, 2023

Yes, But this is not good question again....Area 20 should recieve Area 5 routes..Area 20 is not Buisniss partner network...You should filter on ASBR(R5), or second concept of meaning is OUT direction to Area 20(but not right in prefix meaning)...for me unclear question

[Removed]Option: B
Jan 9, 2024

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.

HarwinderSekhonOption: C
Aug 19, 2023

I am going with C, Why- We need to have routes in area 20 but block it from going into bussiness partner network. If you filter inbound, you block it from being injected to area20 but question says you need to have it in all areas.

ColmenarezOption: B
Sep 12, 2023

B is correct

fizzerOption: B
Sep 13, 2023

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

Fenix7Option: C
Sep 13, 2023

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

Mishranihal737Option: C
Oct 3, 2023

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

MJM1973Option: B
Dec 2, 2023

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

Coffee_bean_masterOption: C
May 27, 2024

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.

Coffee_bean_master
May 27, 2024

Placing the filter on R2 (ABR) in the "OUT" position.

dapardoOption: B
Jun 2, 2024

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

guy276465281819372Option: C
Jul 26, 2023

c is the answer

bk989Option: B
Mar 16, 2024

"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

XBfoundXOption: C
Jul 1, 2024

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.

SeMo0o0o0Option: B
Jul 20, 2024

B is correct