Which command allows a Linux system to capture live network traffic?

The correct choice for capturing live network traffic in a Linux system is tcpdump. This command-line utility is used for packet analysis and allows users to intercept and display the packets being transmitted or received over a network interface.

When executing tcpdump, you can specify various parameters, such as the network interface to monitor, filters to determine which packets to capture, and even the output format of the captured data. This makes tcpdump a powerful tool for network administrators and security analysts to troubleshoot issues and analyze network performance.

In contrast, the other options do not serve the purpose of capturing live traffic. For instance, dig is primarily used for querying DNS information, ipconfig is a command applicable to Windows systems that displays network configuration settings, and nslookup is used to query DNS servers for information about domain names, but none of these commands provide functionality to capture and analyze live network packet data.