hardMultiple ChoiceObjective-mapped
300-410 Practice Question: R1 and R2 are connected via an IPsec VPN tunnel
R1 and R2 are connected via an IPsec VPN tunnel. They are running EIGRP over the tunnel. R1's show ip eigrp neighbors shows R2 as up, but R1's show ip eigrp topology shows all routes from R2 in passive state. However, R1's show ip route does not have any EIGRP routes from R2. What is the root cause?
⚠ Common exam trap
The trap here is that candidates see routes in the EIGRP topology table as passive and assume they are installed in the routing table, but Cisco tests the distinction between the topology table (which stores all learned routes) and the routing table (which only stores feasible successors with valid metrics).
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
✓
R2 is using a route-map to set EIGRP metric to 4294967295, making routes inaccessible.
The EIGRP metric of 4294967295 is the maximum possible metric (32-bit value), effectively making the route unreachable. When R2 applies a route-map to set this metric, R1 receives the routes but considers them inaccessible, so they appear in the topology table as passive (since the neighbor is up and the route is learned) but are not installed in the routing table. This matches the symptoms: neighbor adjacency is established, routes are in the topology table, but no EIGRP routes appear in the IP routing table.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
R2 is using a route-map to set EIGRP metric to 4294967295, making routes inaccessible.
Why this is correct
EIGRP routes with metric 4294967295 are considered unreachable and are not installed in the routing table, even though they appear in topology.
- ✗
EIGRP variance is set to 1, preventing load balancing.
Why it's wrong here
Variance affects load balancing, not route installation.
- ✗
The tunnel interface is down on R2.
Why it's wrong here
If tunnel were down, EIGRP neighbor would not be up.
- ✗
R1 has a passive interface for the tunnel.
Why it's wrong here
Passive interface would prevent R1 from sending hellos, but neighbor is up.
Quick reference
Routing Protocol Comparison
| Protocol | Metric | Max Hops | Algorithm | Type |
|---|---|---|---|---|
| RIP v2 | Hop count | 15 | Bellman-Ford | Distance vector |
| OSPF | Cost (bandwidth) | Unlimited | Dijkstra (SPF) | Link state |
| EIGRP | Composite metric | Unlimited | DUAL | Hybrid |
| IS-IS | Cost | Unlimited | Dijkstra | Link state |
| BGP | Policy / attributes | Unlimited | Path vector | Path vector |
RIP's 15-hop limit makes it unsuitable for large networks. OSPF and EIGRP dominate modern enterprise deployments.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
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.