by David Strom
Trying to analyze traffic on your switched Ethernet network? Until recently, you have either had to spend a lot of money or go without the proper tools. Lantronix' LNA6 network analyzer can help, but getting it working will take some doing.
In the past, analyzers and switches didn't usually mix: analyzers need to listen for traffic on the same network segment and don't see traffic through the other side of the switch. This means either moving your analyzer's connection to your network around in your wiring closet or else placing lots of probes around your enterprise. The cost of these probes can add up, which is why the LNA6 is attractive. It comes with six built-in AUI ports that can be connected to various segments, for a price of $3,995.
However, you do get what you pay for in terms of user interface and usability. I had trouble getting the unit configured and installed: for example, the CD-ROM setup routine bombed out because it was missing a file, and the unit kept forgetting my access password until I upgraded its firmware.
Lantronix' documentation is somewhat skimpy and occasionally incorrect. On the whole I thought the product lacked a certain polish and finish. For instance, why not have six 10BaseT ports instead of AUI ports on the back of the unit? (My package did come with a single AUI/10BaseT converter, however.)
LNA offers decodes for the more popular protocols, including TCP/IP, NetWare, AppleTalk, and DECnet. But the real advantage of the unit is its variety of application-layer filters that can be helpful in tracking down networking problems, eliminating normal traffic from the display. For example, you can filter on web-based traffic, or Lotus' Notes, or net news (NNTP) traffic with a few keystrokes or mouse clicks. And you can setup the unit to send a message to your pager if certain alarm conditions happen, along with replacing the network nodes in the displays with their actual names if you want to take the time to type them in.
The basic functions of monitoring your network, capturing packets, and analyzing them are all here in two different interfaces: a Windows-based graphical display and one that is character-based. The character display can be viewed by several methods: using telnet to the box, attaching an ordinary terminal (or a PC running an asynchronous emulation program) via a serial cable, or connecting a modem to the box and dialing into it via a PC/modem combination. The two interfaces offer somewhat different styles: while the character-based display can be tedious to enter information, it offers a quicker way to view the captured packets than the Windows interface. But then, I am partial to Network General Sniffer's character-mode display, so perhaps there is no accounting for my taste.
Speaking of Sniffer, I thought the LNA held up rather well, given that an equivalent six-port Sniffer would cost much more. LNA doesn't have all the filters nor all the features of a Sniffer, but it comes close enough. And if you need to have multiple network segment monitoring for a reasonable price, Lantronix might be worth looking at.
[[bottom line]]
Fever: in the middle, squarely
Analyzing switched networks at bargain-basement prices, the LNA6 can handle up to 6 different network segments concurrently. It can be somewhat cumbersome to use but overall does the job.
Pros: A variety of interfaces, decode displays and filters in a compact package
Cons: Difficult to setup and configure
Irvine, CA
714 453 3990
714 453 3995 fax
Price: $3996 (six port version tested, a two port version costs $2995)
Platforms: separate unit, monitoring software runs on Windows 3.x and above