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Ethereal 0.10.14

Ethereal is one of the most popular open-source network protocol analyzers around. It's powerful, works on many platforms (something many of its commercial competitors don't do) and it's free. It takes some time to learn but if you want to really know what's going on within your network, it's time well-spent.

The Ethereal community is constantly adding support for new protocols, updating existing ones, fixing vulnerabilities and increasing support for other capture file formats. The latest version of the tool, Ethereal 0.10.14, has added support for 20 new protocols, and adds and updates its capture file support to include DOS Sniffer, Endace ERF, HP-UX nettl, IBM iSeries traces, and Tektronix K12. Among its other significant improvements: When loading a saved capture file, pressing "Cancel" will cause Ethereal to display the packets read up to that point, handy for analyzing parts of very large files. The maximum files allowed in a ring buffer have been increased to 10,000 from 1,024.

I've done plenty of real-world troubleshooting with past versions of Ethereal, and have caught many a worm with it, especially the kind that floods your network with ARP (Address Resolution Protocol) traffic, slowing it down to a crawl. Ethereal is a great tool for fishing out infected nodes simply because it quickly recognizes all the ARP traffic, and you can easily set a filter to pinpoint the nodes generating it.

For this review, I tested the Windows version of Ethereal 0.10.14. First up was a random check on some of the 20 new protocols supported by the latest version of Ethereal, beginning with the UDP Lite protocol. IT is similar to the UDP protocol, but can deliver partially damaged packets to the destination--useful for audio/video streaming applications. To test the UDP Lite dissector (one of the plug-ins Ethereal uses to recognize different protocols), I took a captured sequence containing UDP Lite packets, and loaded it on version 0.10.14, as well as two previous versions of Ethereal. The new version easily identified the specific protocol, while the previous versions could only identify them as IP protocol packets. I then tried opening capture files with CIGI (Common Image Generator Interface), SMB2, and Stanag 5066 protocols. Version 0.10.14 identified all the protocols without any problems.

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