Question 1,607 of 2,152

Route Maps and Route Filtering →hardMultiple ChoiceObjective-mapped

Quick Answer

The answer is that a route-map filtering EIGRP updates on FastEthernet0/1 is preventing neighbor formation. This is correct because the show ip eigrp topology and show ip route outputs confirm that Router R1 has learned the 10.10.10.0/24 route from neighbor 10.1.1.2 via FastEthernet0/0, yet show ip eigrp interfaces reveals zero peers on FastEthernet0/1. When an interface has no EIGRP neighbors but is otherwise operational, a route-map applied to that interface—often using distribute-list or prefix-list filtering—can silently block hello packets or route advertisements, stopping adjacency from forming. On the Cisco CCNP ENARSI 300-410 exam, this scenario tests your ability to distinguish between a routing table issue and a neighbor adjacency problem; a common trap is assuming the route is missing when the real failure is at the neighbor layer. Remember the memory tip: “No peers on the link? Check the filter in the blink.”

300-410 Route Maps and Route Filtering Practice Question

This 300-410 practice question tests your understanding of route maps and route filtering. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.

A network engineer runs the following command on Router R1:

R1# show ip eigrp topology 10.10.10.0/24

IP-EIGRP (AS 100): Topology entry for 10.10.10.0/24 State is Passive, Query origin flag is 1, 1 Successor(s), FD is 131072 Routing Descriptor Blocks:

10.1.1.2 (FastEthernet0/0), from 10.1.1.2, Send flag is 0x0

Composite metric is (131072/128256), Route is Internal Vector metric: Minimum bandwidth is 10000 Kbit Total delay is 100 microseconds Reliability is 255/255 Load is 1/255 Minimum MTU is 1500 Hop count is 1

R1# show ip route 10.10.10.0

Routing entry for 10.10.10.0/24 Known via "eigrp 100", distance 90, metric 131072, type internal Last update from 10.1.1.2 on FastEthernet0/0, 00:00:12 ago Routing Descriptor Blocks:

* 10.1.1.2, from 10.1.1.2, 00:00:12 ago, via FastEthernet0/0

Route metric is 131072, traffic share count is 1

R1# show ip eigrp interfaces
Interface         Peers    Xmit Queue   Mean   Pacing Time   Multicast    Pending

Un/Reliable SRTT Un/Reliable Flow Timer Routes Fa0/0 1 0/0 10 0/10 50 0 Fa0/1 0 0/0 0 0/10 50 0

Based on this output, what is a likely issue?

Clue words in this question

Noticing these words before you look at the options changes how you read each choice.

Clue: "minimum / minimize"
Why it matters: Asks for the least resource use — fewest addresses, smallest subnet, lowest overhead. Eliminate over-provisioned options even if they would technically work.

Question 1hardmultiple choice

Study the full EIGRP explanation →

A
EIGRP neighbor on FastEthernet0/1 is not forming due to a route-map filtering updates.
FastEthernet0/1 has 0 peers, indicating no neighbor; a route-map could be blocking hello packets or updates.
B
The route 10.10.10.0/24 is not in the routing table.
Why wrong: It is present in the routing table.
C
The EIGRP process is not running.
Why wrong: The process is running as shown by the topology entry.
D
The metric is too high for the route to be installed.
Why wrong: The route is installed with metric 131072.

Full breakdown with real-world context →

Answer choices

Why each option matters

Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.

Correct answer & explanation

✓

EIGRP neighbor on FastEthernet0/1 is not forming due to a route-map filtering updates.

The route is in the topology table and routing table, but the interface FastEthernet0/1 has 0 peers. This suggests that a route-map filtering EIGRP updates on FastEthernet0/1 may be preventing neighbor formation or route advertisement. The correct answer is that a route-map may be filtering EIGRP updates on FastEthernet0/1.

Key principle: OSPF neighbour adjacency depends on matching area, hello/dead timers, network type, and authentication — IP reachability alone is not enough.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

✓
EIGRP neighbor on FastEthernet0/1 is not forming due to a route-map filtering updates.
Why this is correct
FastEthernet0/1 has 0 peers, indicating no neighbor; a route-map could be blocking hello packets or updates.
Clue confirmation
The clue word "minimum / minimize" in the question point toward this answer.
Related concept
OSPF neighbours must agree on key parameters.
✗
The route 10.10.10.0/24 is not in the routing table.
Why it's wrong here
It is present in the routing table.
✗
The EIGRP process is not running.
Why it's wrong here
The process is running as shown by the topology entry.
✗
The metric is too high for the route to be installed.
Why it's wrong here
The route is installed with metric 131072.

Common exam traps

Common exam trap: OSPF can fail even when IP connectivity looks correct

OSPF neighbour formation depends on matching areas, timers, network type, authentication and passive-interface behaviour. Do not choose an answer only because the devices can ping.

Trap categories for this question

Command / output trap
The process is running as shown by the topology entry.

Detailed technical explanation

How to think about this question

OSPF questions usually test the details that control adjacency and route selection. Read the neighbour state, area, router ID and interface configuration before deciding what is wrong.

KKey Concepts to Remember

OSPF neighbours must agree on key parameters.
Router ID selection can affect neighbour relationships and LSDB output.
OSPF cost influences the preferred path.
A route can appear in OSPF information but not become the installed route.

TExam Day Tips

Check area mismatch first when OSPF adjacency fails.
Review passive interfaces when a network is advertised but no neighbour forms.
Use show ip ospf neighbor and show ip route clues carefully.

Key takeaway

OSPF neighbour adjacency depends on matching area, hello/dead timers, network type, and authentication — IP reachability alone is not enough.

Real-world example

How this comes up in practice

A network engineer at a university connects two campus buildings via a fibre link. Both routers run OSPF, but no adjacency forms — even though both routers can ping each other. The engineer finds one router is in area 0 and the other in area 1. OSPF adjacency requires matching area numbers, hello/dead timers, and network type. IP reachability alone is not enough.

What to study next

Got this wrong? Here's your next step.

Review OSPF neighbour requirements — matching area type, hello and dead timers, network type, stub flags, and authentication. Study show ip ospf neighbor states (INIT, 2-WAY, FULL). Then practise related 300-410 OSPF questions on adjacency and route selection.

Related 300-410 practice-question pages

Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.

Layer 3 Technologies practice questions

Practise 300-410 questions linked to Layer 3 Technologies.

EIGRP Troubleshooting practice questions

Practise 300-410 questions linked to EIGRP Troubleshooting.

OSPF Troubleshooting (v2/v3) practice questions

Practise 300-410 questions linked to OSPF Troubleshooting (v2/v3).

BGP Troubleshooting practice questions

Practise 300-410 questions linked to BGP Troubleshooting.

Route Redistribution practice questions

Practise 300-410 questions linked to Route Redistribution.

Policy-Based Routing (PBR) practice questions

Practise 300-410 questions linked to Policy-Based Routing (PBR).

VRF-Lite practice questions

Practise 300-410 questions linked to VRF-Lite.

Route Maps and Route Filtering practice questions

Practise 300-410 questions linked to Route Maps and Route Filtering.

Administrative Distance practice questions

Practise 300-410 questions linked to Administrative Distance.

Route Summarization practice questions

Practise 300-410 questions linked to Route Summarization.

Bidirectional Forwarding Detection (BFD) practice questions

Practise 300-410 questions linked to Bidirectional Forwarding Detection (BFD).

VPN Technologies practice questions

Practise 300-410 questions linked to VPN Technologies.

Practice this exam

Start a free 300-410 practice session

Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.

10 questions 20 questions 30 questions 50 questions Timed 30

300-410 practice-test guide →Study guide →Browse all practice tests

FAQ

Questions learners often ask

What does this 300-410 question test?

Route Maps and Route Filtering — This question tests Route Maps and Route Filtering — OSPF neighbours must agree on key parameters..

What is the correct answer to this question?

The correct answer is: EIGRP neighbor on FastEthernet0/1 is not forming due to a route-map filtering updates. — The route is in the topology table and routing table, but the interface FastEthernet0/1 has 0 peers. This suggests that a route-map filtering EIGRP updates on FastEthernet0/1 may be preventing neighbor formation or route advertisement. The correct answer is that a route-map may be filtering EIGRP updates on FastEthernet0/1.

What should I do if I get this 300-410 question wrong?

Are there clue words in this question I should notice?

Yes — watch for: "minimum / minimize". Asks for the least resource use — fewest addresses, smallest subnet, lowest overhead. Eliminate over-provisioned options even if they would technically work.

What is the key concept behind this question?

OSPF neighbours must agree on key parameters.

About these practice questions

Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →

How Courseiva writes practice questions · Editorial policy

Keep practising

Question Discussion

Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.

Loading comments…

This 300-410 practice question is part of Courseiva's free Cisco certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 300-410 exam.