Chapter 4. Capturing Live Network Data
4.1. Introduction
Capturing live network data is one of the major features of Ethereal.
The Ethereal capture engine provides the following features:
•Capture from different kinds of network hardware (Ethernet, Token Ring, ATM, ...).
•Stop the capture on different triggers like: amount of captured data, captured time, captured number of packets.
•Simultaneously show decoded packets while keep on capturing.
•Filter packets, reducing the amount of data to be captured, see Section 4.8, “Filtering while cap- turing”.
•Capturing into multiple files while doing a long term capture, and in addition the option to form a ringbuffer of these files, keeping only the last x files, useful for a "very long term" capture, see Section 4.6, “Capture files and file modes”.
The capture engine still lacks the following features:
•Simultaneous capturing from multiple network interfaces (however, you can start multiple in- stances of Ethereal and merge capture files later).
•Stop capturing (or doing some other action), depending on the captured data.
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