Workshop

appropriate action:
• Network utilization too high?—Seek and destroy the “top talker” using an analyzer.
• Network errors too high?—Seek and destroy the top error producer using an analyzer. Also
check the cabling.
• Server paging too high?—Decrease the number of users or apps on the server or add more
memory.
• Server waiting for I/O too high?—Upgrade the disk cache or consider a new high-performance
disk upgrade.
• Server CPU utilization too high?—Decrease the number of users or apps on the server, add
CPUs, or replace the server.
Summary
Although troubleshooting slowness problems can seem to be a black art, when you break down any
network session into its component parts in a variation on the divide-and-conquer theme, it quickly
becomes apparent which part is the bottleneck on your information highway.
Your family trip can take a lot longer to complete than you expect due to highway traffic or road
conditions. Similarly, your application can move slowly due to a variety of reasons—the most obvious
being network utilization. Other reasons include server slowdown, router or switch latency, and
application or protocol efficiency problems.
Baselining your network is an important step in being able to quickly determine which of these reasons is
causing your slowdown; if you don’t know how things are when life is great, you have no reference to
troubleshoot by. With a baseline, you can compare current stats to “normal” stats—just as a doctor does
when diagnosing your blood chemistry—and quickly take action to fix it. You can “manually” take
baselines, or you can buy into an SNMP management package that will create the baseline for you.
SNMP is certainly the yummier option; however, it’s possible to do this on the cheap side—it’s just more
of a pain in the neck.
Workshop
Q&A
Q Which network analyzers can be used to manually baseline a network segment?
A Just about all the newer ones. The exact technique may vary, but the basic functions for gathering
statistics about the segment you’re analyzing are the same. Very old DOS-based analyzers might not
have the ability to save statistics over a time frame, however. Just ask before you buy.