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Getting started using your GigaStor
Chapter 2: Getting started 193
makes the charts display every interval in which the bits were
present from your packet, not just the first interval.
This setting works even if it was not enabled when the packet
was captured. It can be enabled later and you will see every
interval where a bit was present.
You set the general options for your GigaStor system. These options have a large
effect on the operation of the GigaStor system, so if anything seems wrong or
you are not seeing all the packets you anticipated, return to these settings and
see if they should be changed.
Shorten your time slice to find a top talker
The Top Talker list may appear to be missing entries. This occurs because of a
combination of two settings in your GigaStor Control Panel. Temporarily adjust
these settings to get the data you want.
If you are trying to find what system or systems are responsible for certain
traffic on your network, you’d typically use Top Talkers to identify them. There
is, however, a limit to the number of systems that Top Talkers identifies. By
default, that limit is 1000. As soon as the 1000th system is identified in a time
slice—chronologically—all remaining systems are ignored even if they were
“chattier” (that is, causing more traffic on the network) than any of the first 1000
systems. In other words, the GigaStor Control Panel does not show the 1000 most
talkative systems, but the first 1000 systems it encounters.
The solution is to shorten your time slice, perhaps down to milliseconds
if necessary so that the Top Talker list does not reach the 1000 stations.
Additionally, you can increase the number of IP Addresses allowed in the list up
to a maximum of 200,000.
Also keep in mind that in the GigaStor Control Panel you are looking at statistics,
not actual packet data. Therefore, you could set the GigaStor Control Panel
sampling ratio to 1 and set the maximum number of entries allowed to a very
high number (100,000 or even higher). This won’t give you 100% accurate data,
but you will get a very good idea of the situation based on statistics.
Caution: If you change the maximum IP address or sampling ratio, consider
changing its value back after you have identified your top talker. The reason
is that both settings affect memory and can adversely affect performance
if there is a high number of IP address and extremely low sampling ratio.
Returning these values to their defaults (10,000 IP Addresses and a sampling
ratio of 10) will restore GigaStor performance.
The GigaStor Control Panel indexing maximums and sampling ratio are
configured in Setting the GigaStor general options (page 189) .
Understanding GigaStor protocol and port settings
Allow the GigaStor to get smarter by collecting more information. Over time as
the GigaStor sees more of your network’s traffic, it gets smarter about the traffic
on your network.
Unless you have a specific reason to do so, we recommend that you leave these
options selected:
Enable intelligent TCP protocol determination —when checked, all new data
collected is indexed by protocol, only if SYN-SYNACK-ACK packets are observed