captest - Linux
Overview
captest is a command-line tool for capturing and analyzing network traffic. It can be used for troubleshooting network connectivity issues, monitoring traffic patterns, and identifying potential security threats.
Syntax
captest [options] [interface] [filter]
Options/Flags
- -c, –count: Capture X packets and exit.
- -i, –interface: Network interface to capture traffic from.
- -f, –filter: BPF filter to apply to captured traffic.
- -t, –timeout: Number of seconds to capture traffic for. Default: 10
- -s, –snaplen: Maximum size of packets to capture. Default: 65535
- -w, –write: File to write captured packets to.
- -r, –read: File to read captured packets from.
- -h, –help: Display help and usage information.
Examples
Simple capture:
captest
Capture on specific interface:
captest -i eth0
Apply BPF filter:
captest -f "host example.com"
Limit packets count:
captest -c 100
Capture to file:
captest -w my_capture.pcap
Read packets from file:
captest -r my_capture.pcap
Common Issues
- No traffic captured: Ensure the specified network interface is up and running.
- Invalid BPF filter: Check the syntax of your filter expression.
- Large capture file: Monitor traffic for only as long as necessary and use filters to reduce captured data.
Integration
Analyze with Wireshark:
captest -w capture.pcap && wireshark -r capture.pcap
Extract traffic statistics:
captest -c 1000 | tcpdump -nn -c 1000 | cut -d " " -f 8,11,13,14 | sort -k 2
Related Commands
- tcpdump
- Wireshark
- netstat