ICND1 Infrastructure Maintenance 5 — Questions and Answers
Question 1: Which SNMP version introduced strong authentication and encryption for secure network management?
- SNMPv1
- SNMPv2c
- SNMPv3 (Correct answer)
- SNMPv4
Correct answer: SNMPv3
SNMPv3 added user-based security with MD5/SHA authentication and DES/AES encryption, unlike the community-string-based v1 and v2c.
Question 2: A Cisco device sends an unsolicited SNMP message to the NMS when an interface goes down. What is this message called?
- SNMP Get
- SNMP Set
- SNMP Trap (Correct answer)
- SNMP Inform
Correct answer: SNMP Trap
An SNMP Trap is an unsolicited notification sent from the agent to the NMS when a significant event occurs.
Question 3: What is the purpose of the Management Information Base (MIB) in SNMP?
- Stores SNMP community strings for authentication
- Defines the hierarchical database of managed objects on a device (Correct answer)
- Provides encryption keys for SNMPv3
- Maps IP addresses to SNMP agent ports
Correct answer: Defines the hierarchical database of managed objects on a device
The MIB is a structured database that defines all the variables (objects) that can be monitored or configured via SNMP.
Question 4: Which protocol and port does SNMP use for NMS-to-agent queries?
- TCP port 161
- UDP port 161 (Correct answer)
- TCP port 162
- UDP port 162
Correct answer: UDP port 161
SNMP uses UDP port 161 for NMS-to-agent queries (Get/Set), while traps and informs use UDP port 162.
Question 5: An administrator uses 'snmp-server community PUBLIC ro' in global config. What does 'ro' specify?
- Read-only access — the NMS can only retrieve data, not modify it (Correct answer)
- Remote-only access — only remote NMS stations can use this community
- Router-only — restricts SNMP to the router itself
- Redundant operation — enables SNMP failover
Correct answer: Read-only access — the NMS can only retrieve data, not modify it
The 'ro' keyword grants read-only community access, allowing the NMS to perform Get operations but not Set operations.
Question 6: Which command on a Cisco router verifies that SNMP is enabled and shows configured community strings?
- show snmp
- show snmp community (Correct answer)
- debug snmp packets
- show protocols snmp
Correct answer: show snmp community
The 'show snmp community' command displays all configured SNMP community strings and their access levels.
Question 7: A technician uses Cisco IOS NetFlow on a router interface. What is the primary purpose of NetFlow?
- Block unwanted traffic flows with ACLs
- Collect and export IP traffic statistics for analysis and accounting (Correct answer)
- Balance traffic load across multiple interfaces
- Encrypt traffic flows between routers
Correct answer: Collect and export IP traffic statistics for analysis and accounting
NetFlow collects detailed per-flow traffic statistics (source/destination IP, ports, protocol) and exports them to a collector for analysis.
ICND1 Infrastructure Maintenance 5
Which SNMP version introduced strong authentication and encryption for secure network management?