hardMultiple Choice
300-410 Practice Question: An engineer configures SNMPv2c with a read-only…
An engineer configures SNMPv2c with a read-only community string 'public' on a router. The NMS can poll interface statistics, but when trying to poll OSPF neighbor states, the NMS receives no response. Which is the most likely explanation?
⚠ Common exam trap
Cisco often tests the misconception that SNMP community strings or views are the only reason for MIB access failures, when in fact the MIB itself may not be loaded or supported on the device.
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
✓
The OSPF MIB is not supported or not loaded on the router.
The most likely explanation is that the OSPF MIB is not supported or not loaded on the router. SNMPv2c with a read-only community string 'public' can poll standard interface MIB objects (like ifEntry) because those are part of the base IF-MIB, which is always loaded. However, OSPF neighbor states are defined in the OSPF-MIB (RFC 1850/4750), which is an enterprise-specific MIB that must be explicitly supported and loaded in the router's SNMP agent. If the OSPF MIB is not present, the agent will not respond to GET requests for OSPF-related OIDs, even though the community string has read-only access.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
The OSPF MIB is not supported or not loaded on the router.
Why this is correct
The OSPF MIB is not necessarily available on every Cisco IOS image; the router must be running OSPF and the MIB must be instantiated in the SNMP agent for the OSPF process. In many Cisco IOS versions, you must issue 'snmp-server enable traps ospf' or have an active OSPF process to load the OSPF-MIB; otherwise, snmpwalk returns `no such object` or `no such variable`. Therefore, the poll fails even if the community string and SNMP settings are correct.
- ✗
The community string 'public' is not allowed to access the OSPF MIB due to a missing 'snmp-server view' command.
Why it's wrong here
A missing 'snmp-server view' command does not deny the 'public' community access; by default, the 'public' community string is mapped to the default view, which includes the entire Internet OID tree and thus all OSPF-MIB objects. To block access, an administrator must explicitly create a view that excludes the OSPF-MIB and then apply that view with 'snmp-server group' or a community-to-view mapping. The absence of a view simply leaves the permissive default in place, so this is not the reason for the SNMP failure.
- ✗
OSPF neighbor states are only available via SNMPv3 due to security restrictions.
Why it's wrong here
OSPF neighbor-state objects are not gated by SNMP version; SNMPv2c and SNMPv3 both expose the same OSPF-MIB content. The real requirements are that the OSPF MIB is loaded and that the SNMP community (for v2c) or user/group configuration (for v3) has read access to the OSPF-MIB subtree. Security restrictions such as views and ACLs are independent of SNMP transport security and would apply equally to both versions.
- ✗
The NMS must use the OSPF process ID in the OID to poll neighbor states.
Why it's wrong here
The OSPF-MIB's OSPF neighbor table (ospfNbrTable) is indexed by the neighbor IP address and the associated OSPF router ID, not by the local OSPF process ID. The process ID is a Cisco IOS artifact used in configuration and does not appear in standard MIB II (RFC 1850/4750) OIDs. The NMS must instead build OIDs using the OSPF Router ID for the ospfGeneralGroup and the neighbor address for the ospfNbrEntry, so specifying a process ID would produce an invalid OID.
Visual reference
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.
Go deeper
Related to this question
About these practice questions
One of 1,401 original 300-410 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
JA
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.