Configuring Packet Capture

Packet capture is a tool that helps you to analyze network traffic and troubleshoot network problems. The packet capture tool captures real-time data packets traveling over the network, for monitoring and logging.

Packets are captured as binary data, without modification. You can read the packet information offline with a packet analyzer such as Ethereal or tcpdump.

If you need to quickly capture packets destined for or originating from the Routing Engine and analyze them online, you can use the J-Web packet capture diagnostic tool. For more information, see Capturing and Viewing Packets with the J-Web Interface.

Note: The packet capture tool does not support IPv6 packet capture.

You can use either the J-Web configuration editor or CLI configuration editor to configure packet capture. For more information about packet capture, see the JUNOS Policy Framework Configuration Guide.

For information about which devices support the features documented in this chapter, see Support Overview for Administration Features.

This chapter contains the following topics.

• Packet Capture Terms
• Packet Capture Overview
• Before You Begin
• Configuring Packet Capture with a Configuration Editor
• Changing Encapsulation on Interfaces with Packet Capture Configured
• Verifying Packet Capture