Capsa Network Analyzer
The 10.0 version of Capsa Network Analyzer is available as a free download on our software library. The most recent installation package that can be downloaded is 127.1 MB in size. The software is included in Internet & Network Tools. The actual developer of the program is Colasoft LLC. Our antivirus analysis shows that this download is malware free.
From the developer:
Capsa is an easy-to-use Ethernet packet sniffer (network analyzer or network sniffer) for network monitoring and troubleshooting purposes. It performs real-time packet capturing, 24/7 network monitoring, reliable network forensics, advanced protocol analyzing, in-depth packet decoding, and automatic expert diagnosing.
You may want to check out more software, such as Unsniff Network Analyzer, HHD Software Free Network Analyzer or Genetic Network Analyzer, which might be similar to Capsa Network Analyzer.