User's Manual

710 CHAPTER 17: USING 3COM NETWORK DIRECTOR ON A MULTI-SITE NETWORK
In order to cope with this situation you will need to first determine the
most common configuration. In the example given above, this would
likely be the devices monitored in response monitoring mode. The
monitoring modes and poll rates for the subnet should be configured to
match the settings selected as the most common. Having done this you
will then need to override the subnet settings for each device that is on
that subnet, but to which the subnet’s settings are not applicable.
It is only really necessary to override the subnet settings for a device to
which the subnet’s settings are not applicable if you intend to monitor
that device. In the example given above you may decide that you will not
monitor end stations, in which case it would not be necessary to override
the subnet settings for those devices if you determined that they should
use a different monitoring mode or poll rate from that configured for the
subnet.
Routers and layer-3 switches inherit their settings from the whole map
settings, not from the subnets that they are members of. As a result, in
order to configure the correct settings for all devices at a site you will
need to apply the settings not only to each subnet that covers that site,
but also to each router and layer-3 switch that is located at that site.
If you have determined that the appropriate monitoring modes and poll
rates for a large number of remote sites are identical then it may be
quicker and easier to configure the monitoring mode and poll rate
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 monitoring modes are identical and the poll rates are
similar, simply by examining the poll rates determined for each device
type at each of the remote sites and selecting appropriate compromise
poll rates.
Configuring
Discovery
Configuring Discovery Options in Multi-Site Networks
The Network Discovery wizard contains several options that allow the
Network Discovery process to be tuned according to the requirements of
the network being discovered:
■ The subnets to be discovered can be controlled. Note that it is not
necessary to discover whole subnets; IP address ranges within subnets