NE NE Network Management and Monitoring 2 — Questions and Answers
Question 1: What is the purpose of NTP (Network Time Protocol) in a managed network?
- To synchronize clocks across all network devices for consistent log timestamps and security operations (Correct answer)
- To provide DHCP failover between servers
- To schedule configuration backups across devices
- To synchronize routing tables between routers
Correct answer: To synchronize clocks across all network devices for consistent log timestamps and security operations
NTP synchronizes device clocks to a reference time source, ensuring accurate log timestamps, certificate validity checks, and security event correlation.
Question 2: What is SNMP trapping used for?
- Polling device MIBs on a schedule
- Allowing devices to proactively send unsolicited alerts to the NMS when specific events occur (Correct answer)
- Encrypting SNMP management traffic
- Preventing unauthorized SNMP access
Correct answer: Allowing devices to proactively send unsolicited alerts to the NMS when specific events occur
SNMP traps enable devices to immediately notify the NMS of critical events (link down, threshold crossed) without waiting for the next polling cycle.
Question 3: What does RSPAN (Remote SPAN) allow compared to standard SPAN port mirroring?
- RSPAN allows mirroring traffic to a port on a different switch across the network (Correct answer)
- RSPAN filters mirrored traffic by VLAN
- RSPAN encrypts mirrored traffic before forwarding it
- RSPAN mirrors traffic in both directions simultaneously
Correct answer: RSPAN allows mirroring traffic to a port on a different switch across the network
RSPAN extends port mirroring across multiple switches using a dedicated VLAN, allowing a network analyzer connected to a remote switch to capture traffic from source ports.
Question 4: Which protocol is used to provide centralized device authentication and authorization using a TCP-based connection with encrypted payloads?
- RADIUS
- TACACS+ (Correct answer)
- LDAP
- Kerberos
Correct answer: TACACS+
TACACS+ uses TCP port 49 and encrypts the entire payload, providing separate AAA functions; it's preferred over RADIUS for device administration.
Question 5: What is the purpose of a network management VLAN (or out-of-band management network)?
- To provide higher bandwidth for management traffic
- To separate management traffic from user data traffic, reducing the attack surface (Correct answer)
- To assign static IPs to all network devices automatically
- To enable routing between management systems and user devices
Correct answer: To separate management traffic from user data traffic, reducing the attack surface
An out-of-band management network or dedicated management VLAN isolates device administration from production traffic, reducing security risk and ensuring management access during outages.
Question 6: What is the function of LLDP (Link Layer Discovery Protocol)?
- To negotiate trunk and access port modes between switches
- To allow network devices to advertise identity and capability information to directly connected neighbors (Correct answer)
- To detect and prevent Layer 2 switching loops
- To dynamically assign VLANs based on device type
Correct answer: To allow network devices to advertise identity and capability information to directly connected neighbors
LLDP (IEEE 802.1AB) is a vendor-neutral protocol that lets devices announce their identity, capabilities, and connected port info to adjacent devices for topology discovery.
NE NE Network Management and Monitoring 2
What is the purpose of NTP (Network Time Protocol) in a managed network?