What is the purpose of a network sniffer?

A network sniffer is a tool used to capture and analyze network traffic. Its primary purpose involves monitoring data packets as they traverse a network, allowing network administrators or security professionals to inspect the contents of these packets for analysis, troubleshooting, and security assessments. By using a network sniffer, one can identify issues such as performance bottlenecks, unauthorized access attempts, or data breaches by seeing the interactions between devices and the data being sent and received.

The other options do not accurately describe the function of a network sniffer. Encrypting sensitive data during transmission relates to ensuring data confidentiality and integrity, which is a different process altogether. Blocking unauthorized access attempts pertains to firewall and intrusion prevention systems rather than passive monitoring tools. Lastly, creating backups of network devices is a completely separate activity that focuses on data recovery and system integrity, rather than real-time traffic capture and analysis.