When diagnosing a VM receiving XML data, which tool is best to start capturing and analyzing traffic on the wire?

• A. Tcpdump
• B. Netstat
• C. Ping
• D. Traceroute

Answer: (A)

Packet capture is essential when diagnosing why a VM is receiving XML data. It lets you see every packet on the wire, including headers, payloads, timing, and whether the data arrives in the expected format. Tcpdump is the best starting point because it runs on the command line, captures live traffic on a specific interface, and lets you filter to the traffic you care about (for example, by protocol, port, or even content). With tcpdump you can print payloads or save a full capture for deeper analysis in a tool like Wireshark, enabling you to verify that XML is actually arriving, that it’s well-formed, and to identify issues such as missing data, incorrect ports, or protocol mismatches. Other options don’t provide on-wire traffic capture or detailed payload analysis: netstat shows current connections but not the traffic itself, ping tests reachability, and traceroute reveals the path rather than the actual data being transmitted.