Explanation/Reference:
Section: Design Methodologies Explanation
Explanation:
Of the choices available, determining the number of bytes transmitted by an interface on a network device is best achieved with Simple Network Management Protocol (SNMP). SNMP is used to monitor and manage network devices by collecting data about those devices. The data is stored on each managed device in a data structure known as a Management Information Base (MIB). A network management station (NMS) can periodically poll a managed device to accumulate historical data that can then be analyzed to determine whether the managed device requires optimization. Because SNMP cannot store historical data locally and requires polling by an NMS to accrue historical data, it is considered a pull-based network management protocol. By contrast, a push-based network management protocol can periodically send data to an NMS. The Cisco NetFlow feature is an example of a push-based protocol.
Monitoring IP version 4 (IPv4) traffic flows through an interface on a Cisco device is best achieved with NetFlow, not SNMP. NetFlow is a Cisco IOS feature that can be used to monitor traffic flows. A traffic flow is defined as a series of packets with the same source IP address, destination IP address, protocol, and Open Systems Interconnection (OSI) Layer 4 information. NetFlow gathers flow-based statistics such as packet counts, byte counts, and protocol distribution. The data gathered by NetFlow is typically exported to management software. You can then analyze the data to facilitate network planning, customer billing, and traffic engineering.
Identifying the nearest interface on an adjacent Cisco device is best achieved with Cisco Discovery Protocol (CDP), not SNMP. CDP is a Cisco-proprietary Layer 2 protocol that is supported on all Cisco- manufactured hardware. CDP-enabled devices periodically send advertisements out of each CDP-enabled interface. These CDP advertisements contain information about the sending device and its capabilities.
When a CDP-enabled device on the network segment receives a CDP advertisement, the device updates its internal list of neighboring CDP-enabled devices.
Verifying IPv4 connectivity to an adjacent network device is best achieved with Internet Control Message Protocol (ICMP), not SNMP. ICMP uses several message types to provide information regarding network connectivity between devices. The following types of packets are sent by ICMP:
ICMP Destination Unreachable -When a networked destination host is unreachable, a router or host

sends an ICMP Destination Unreachable message to the source host.
ICMP Redirect -When more than one gateway to a destination host exists, inferior gateways send an

ICMP Redirect message to inform the source host that a better gateway exists.
ICMP Echo -When a source host attempts to verify connectivity to a destination host, the source host

sends an ICMP Echo Request message to determine whether a destination host is reachable. If the destination host is reachable, the destination host sends an ICMP Echo Reply message to the source host.
Reference:
CCDA 200-310 Official Cert Guide, Chapter 15, Simple Network Management Protocol, pp. 619-624 Cisco: How To Calculate Bandwidth Utilization Using SNMP
Cisco: Performance Management: Best Practices White Paper: Measure Utilization