ENARSI Exam - Question 78

Question

Refer to the exhibit. An engineer has configured R1 as EIGRP stub router. After the configuration, router R3 failed to reach to R2 loopback address.

Which action advertises R2 loopback back into the R3 routing table?

Examice · Accepted Answer

The correct action to advertise R2's loopback back into the R3 routing table involves adding a static route for R2's loopback address in R1 and redistributing it to advertise to R3. This process ensures that R1, configured as an EIGRP stub, contains the necessary route information, which it can then pass on to R3. The commands required for this configuration include 'redistribute static' and 'eigrp stub static' to facilitate proper route advertisement in a stub scenario.

TECH3K3 · Answer

Answer is B - as I lab it.

I was thinking it was another answer but the lab pointed me to the right direction.

ip access-list standard R2LO
  permit 2.2.2.2
 !
 route-map R2LO_LEAK permit 10
  match ip address R2LO
  !         
  router eigrp 1
   network 1.1.1.1 0.0.0.0
   network 192.168.12.0
   network 192.168.13.0
   eigrp stub connected summary leak-map R2LO_LEAK

HungarianDish_111 · Answer

For me "A" is correct.  I labbed it in CML. "B" is incorrect, because there is no such distribute-list (as others pointed out). Pls, see some good explanations here:

https://community.cisco.com/t5/routing/eigrp-eigrp-stub-connected-static-summary/td-p/2575321
https://learningnetwork.cisco.com/s/question/0D53i00000Kso40CAB/clarification-needed-on-eigrp-stub-static-option
https://notes.networklessons.com/redistribute-static-route-into-eigrp-stub-router

jansan55 · Answer

As previously mentioned (for example by HungarianDish) there is no such possibilty eigrp leak-map with distribute list. I also labbed the configuration, and I agree with HungarianDish, that answer is "A". Even the wording is met.

louisvuitton12 · Answer

Option B is correct:
https://networklessons.com/cisco/ccie-routing-switching-written/eigrp-stub-leak-map

jthompaf · Answer

I agree the correct answer is B. C would work if the config was on R1 and not R3.

doron1122 · Answer

A
https://community.cisco.com/t5/routing/eigrp-eigrp-stub-connected-static-summary/td-p/2575321

Huntkey · Answer

B says applied with a distribute-list and that is incorrect, isn't it?

xziomal9 · Answer

The correct answer is: B

Reikidude00 · Answer

redistribution of staic routes not work with stub . 
The only possible is B

Reikidude00 · Answer

B IS CORRECT

Edwinmolinab · Answer

by default eigrp stub doesn't distribute static for that reason exists eigrp stub static to allow it

doron1122 · Answer

A
https://learningnetwork.cisco.com/s/article/eigrp-stub-routing

ntdevera · Answer

Its B 
Redistributing static routes into eigrp isnt enough. If you don't have the "eigrp stub static" configured, it will not advertise the redistributed route. 
Ref: https://learningnetwork.cisco.com/s/article/eigrp-stub-routing

TheBaja · Answer

Answer is C. eigrp stub leak-map MY-ROUTE-MAP make exeption for stub feature.
router eigrp 1
eigrp stub leak-map MY-ROUTE-MAP
route-map MY-ROUTE-MAP permit 10
match ip address MY-ACL
ip access-list standard MY-ACL
permit x.x.x.x  wildcard (loopback network)

zhlzjz · Answer

Use a leak map on R1 that matches the required prefix and apply it with the EIGRP stub feature.

HungarianDish_111 · Answer

My config on R1:
 router eigrp 1
 network 1.1.1.1 0.0.0.0
 network 192.168.12.0
 network 192.168.13.0
 redistribute static
 eigrp stub connected static summary

ip route 2.2.2.2 255.255.255.255 192.168.12.2

You need the static route on R1 to get the prefix 2.0.0.0/32 back into the eigrp table. Plus, you need to push out the static route with these two commands on R1:
   redistribute static
   eigrp stub static

HungarianDish_111 · Answer

After applying the config, that is what you see on R3:

r3#sh ip route eigrp | b Gateway
Gateway of last resort is not set

1.0.0.0/32 is subnetted, 1 subnets
D        1.1.1.1 [90/130816] via 192.168.13.1, 00:13:36, GigabitEthernet0/0
      2.0.0.0/32 is subnetted, 1 subnets
D EX     2.2.2.2 [170/3072] via 192.168.13.1, 00:12:49, GigabitEthernet0/0
D     192.168.12.0/24 [90/3072] via 192.168.13.1, 00:13:36, GigabitEthernet0/0
r3#

HungarianDish_111 · Answer

Using the "redistributed" parameter had the very same effect:
Config on R1:

!
router eigrp 1
 network 1.1.1.1 0.0.0.0
 network 192.168.12.0
 network 192.168.13.0
 redistribute static
 eigrp stub connected summary redistributed

ip route 2.2.2.2 255.255.255.255 192.168.12.2
!

[Removed] · Answer

A and B are correct, but both of them have terrible wording.

A.
If you configure a static route to 2.2.2.2, then that will remove that route from the EIGRP topology due to AD. So even if R1 was not a stub router, it would not advertise the route.
On top of that, we not only have to redistribute static routes into EIGRP, we also need to configure the eigrp stub to advertise static, as follows:

eigrp 
redistribute static 
eigrp stub leak-map R2LOOP

So I think B is the best answer, as A is far too vague.

inteldarvid · Answer

the answer correct is "A"

Brand · Answer

I don't know why but this questions seems like it's asking about leak-map feature of EIGRP stub configuration... I can't explain but I have this feeling maybe it's because there is no other question talking about leak-map. Therefor it's B to me.

[Removed] · Answer

Think the question has being edited - answer is now C (verified in CML)

Marcinko · Answer

There is no such option as distribute-list regarding leak-map, but redistribute command works as HungarianDish labbed: Correct answer is A

jabal93 · Answer

HQ(config-router-af)#do sh run | sec acc
access-list 10 permit 192.168.4.0 0.0.0.255  (R2)
access-list 20 permit 172.16.0.0 0.0.255.255  (R3)
HQ(config-router-af)#

HQ(config-router-af)#do sh run | sec route-m
route-map LEAK-BR2 permit 10
 match ip address 10 20

HQ(config-router-af)#do sh run | sec eig
router eigrp cisco
 !
 address-family ipv4 unicast autonomous-system 10
  !
  topology base
  network 0.0.0.0
  eigrp router-id 5.5.5.5
  eigrp stub connected summary leak-map LEAK-BR2
 exit-address-family

bk989 · Answer

Answer seems to be A.

I will lab to verify on my own but the rest are not correct.
B. there is no distribute-list leak-map command
C. This is applying the change to R3. Since R1 is a stub as well, it is not propagating R2 to R3 routes.
D. If we add a static null route for R2 loopback, we lose reachability to R2 loopback.

tsamoko · Answer

B as everyone is said is not even possible , there is no such a command with distribution list . 
I go with A , for A to work we need to know the configuration of R1 . In order for this to work , we need 
1) to create static route for R2 lo0 
2) under eigrp process , when we are configuring the stub function , we won't just let the default stub, advertising connected and summary. We need to configure " eigrp stub connected static" , then in R3 , we will see as D EX 2.2.2.2  . 
So I only counted that they configure that. A is the answer

Rupirapa · Answer

In my opinion the answer is C

Here is the config I assume is configured on the routers based on the problem

*R1*
router eigrp 10
 network 0.0.0.0
 eigrp stub connected summary leak-map LEAK

ip prefix-list TEST seq 5 permit 2.2.2.2/32

route-map LEAK permit 10
 match ip address prefix-list TEST

*R2*
router eigrp 10
 network 0.0.0.0

*R3*
router eigrp 10
 network 0.0.0.0

A) This is the configuration that this answer is suggesting.
ip route 2.2.2.2 255.255.255.255 192.168.12.2
redistribute static metric 1000000 10 255 1 1500
However, the answer is missing the command "eigrp stub connected static"

B) The command does not exist
R1(config-router)#distribute-list ?
        IP access list number
    IP expanded access list number
  WORD         Access-list name
  gateway      Filtering incoming address updates based on gateway
  prefix       Filter prefixes in address updates
  route-map    Filter prefixes based on the route-map

C) Correct

D) Does not make any sense

Reikidude00 · Answer

anyone can post a configuration of this? The answer should be a leak-map

Adeleke · Answer

correct answer is B
The EIGRP stub feature is useful to prevent unnecessary EIGRP queries and to filter some routes that you
advertise. What if you want to configure your router as a stub router but still make an exception to some
routes that it advertises? That is possible with the leak-map feature.

toto89 · Answer

Leak-map can't be applied to distribute-lists it can only be applied to the stub so B is incorrect. 
A could be correct because R1 stub could be configured to advertise redistributed routes. In that case the route with null0 would be advertised to both routers. The route wouldn't become a successor on R2 because it already has a connected route with an AD of 1 which is lower than 90 so the R2 wouldn't add this route into his routing table. R3 on the other hand would add it to his routing table.

Noproblem22 · Answer

I believe B is correct                                  https://networklessons.com/cisco/ccie-routing-switching-written/eigrp-summary-leak-map

Malasxd · Answer

The answer "A" would work, but "B" makes so much more sense for me.

https://networklessons.com/cisco/ccie-routing-switching-written/eigrp-stub-leak-map

adudeguy · Answer

Answer C.
A & D both require "redistribute static" under EIGRP.  B is wrong because the leak-map is applied to the stub command and not via a distribute list.

XBfoundX · Answer

the only one that can be right is A, the answer B is using a distribute list instead of a route-map that's the bad thing about this.

The point is that we need also to remember that when eigrp stub is enabled by default you can only advertise connected network and summary networks, if we want to redistribute static routes we need to add the command eigrp stub connected summary static

dapardo · Answer

Im going with A on this just because answer B mention distribute list, thats not correct. We should use a prefix list with a route map or something like that.

Fenix7 · Answer

Answer is A. You need these 2 commands: redistribute static and eigrp stub static

[Removed] · Answer

B is correct

jabal93 · Answer

it's a tricky one but the correct answer is A

B: wrong because leak map only works with route-map

AonDuine · Answer

access-list 10 permit 2.2.2.2
route-map LEAK_MAP permit 10
 match ip address 10
router eigrp 1
 distribute-list route-map LEAK_MAP out

d4lv · Answer

R1(config)#ip access-list standard R2_L0
R1(config-std-nacl)#permit host 2.2.2.2
R1(config)#route-map R2_L0_LEAK
R2(config-route-map)#match ip address R2_L0
R1(config)#router eigrp 1
R1(config-router)#eigrp stub leak-map R2_L0_LEAK

ENARSI Exam - Question 78

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