300-410 Free Practice Test

- (Exam Topic 1)
Refer to the exhibit.

A junior engineer updated a branch router configuration. Immediately after the change, the engineer receives calls from the help desk that branch personnel cannot reach any network destinations. Which configuration restores service and continues to block 10.1.1.100/32?

1. A. route-map FILTER-IN deny 5
2. B. ip prefix-list 102 seq 15 permit 0.0.0.0/32 le 32
3. C. ip prefix-list 102 seq 5 permit 0.0.0.0/32 le 32
4. D. route-map FILTER-IN permit 20

Correct Answer: D
By using “deny” keyword in a route-map, we can filter out the prefix specified in the prefix-list. But there is an implicit “deny all” statement in the prefix-list so we must permit other prefixes with “permit” keyword in the route-map.

- (Exam Topic 3)
Refer to the exhibit.

An engineer configured BGP and wants to select the path from 10.77.255.57 as the best path instead
of current best path. Which action resolves the issue?

1. A. Configure AS_PATH prepend for the current best path
2. B. Configure higher MED to select as the best path
3. C. Configure AS_PATH prepend for the desired best path
4. D. Configure lower LOCAL_PREF to select as the best path

Correct Answer: D
From the output, we learn that the current best path is from 10.57.255.11 (which includes “…valid, confed-external, best“) and this path is 2 ASes away (64955 65003). Although there are some paths
with only 1 AS away (path from 172.16.254.234 for example) but they were not chosen the best path so AS_PATH was not used to determine the best path -> Answers A and answer C are not correct. All the paths in the output have metric of 0 and this is the lowest (best) value for this attribute. If we configure higher MED then it is less preferred over other paths -> Answer B is not correct.
Only answer D is left but LOCAL_PREF attribute should be configured with higher value to be preferred so we hope “lower LOCAL_PREF” here means higher value. But this is the best answer.

- (Exam Topic 3)
Refer to the exhibit.

While monitoring VTY access to a router, an engineer notices that the router does not have any filter and anyone can access the router with username and password even though an ACL is configured.
Which command resolves this issue?

1. A. access-class INTERNET in
2. B. ip access-group INTERNET in
3. C. ipv6 traffic-filter INTERNET in
4. D. ipv6 access-class INTERNET in

Correct Answer: D

- (Exam Topic 3)
Refer to the exhibit.


AS111 is receiving its own routes from AS200 causing a loop in the network. Which configuration provides loop prevention?
A)

B)

C)

D)

1. A. Option A
2. B. Option B
3. C. Option C
4. D. Option D

Correct Answer: C
A router discards BGP network prefixes if it sees its ASN in AS-Path as a loop prevention mechanism. The “allowas-in” feature allows routes to be received and processed even if router detects its own ASN in AS-Path.

- (Exam Topic 3)
Which protocol must be secured with MD-5 authentication across the MPLS cloud to prevent hackers from introducing bogus routers?

1. A. MP-BGP
2. B. LSP
3. C. RSVP
4. D. LDP

Correct Answer: A