User's Manual

Configuration 705
may be quicker and easier to configure the Retry/Timeout hierarchy by
configuring the whole map settings for these remote sites and then
override the settings for the local site and any remote sites with different
requirements.
This technique may still be used if you have a large number of remote
sites for which the appropriate numbers of retries and timeout periods
are similar, simply by examining the number of retries and timeout
periods determined for each request type at each of the remote sites and
selecting the largest values.
Configuring
Monitoring Modes
and Poll Rates
When monitoring a remote site, frequent polling of many devices on that
site for large amounts of state information can quickly saturate a slow
WAN link, leading to higher latency and less reliability in contacting the
site.
In order to reduce the impact that monitoring has upon the WAN links
that form the path to a monitored remote site, one or more of the
following actions can be taken:
Reduce the poll rates. This has the effect of reducing the total amount of
requests that will be made across the WAN link, but at the cost of the
accuracy of the monitoring information.
For example, by reducing the poll rate for a device from once every 30
seconds to once every minute you will halve the amount of traffic
generated by the monitoring of that device. However, you will double
the amount of time it will take before 3Com Network Director
determines if there is a problem with the device.
Details of how to configure the poll rates used across your network are
provided in “
Controlling Monitoring Type and Polling Rates” on
page 296
.
Change the monitoring mode. There are three different monitoring
modes available that will provide you with state information about a
device. In order of traffic generated, from most to least, these are: full
monitoring, response monitoring and SNMP traps only. The details of
these three monitoring modes are provided in “
Monitoring Mode” on
page 296
. Changing the monitoring mode for a remote device to one
that generates less traffic reduces the amount of traffic that is generated
across the WAN link by each monitoring poll for that device (or, in the