3Com 3C15500 - Network Director User Manual page 716

712 C 17: U 3C N D O A M -S N
HAPTER SING OM ETWORK IRECTOR N ULTI ITE ETWORK
In order to discover a single device, 3Com Network Director queries the
device for information about its features, current configuration and other
devices that are known to it. This can generate a large amount of traffic,
particularly for complex devices.
If you discover all of the devices on all of the subnets at a remote site
then this has the potential to increase the utilization of the WAN links in
the path to that site to the point where it has a noticeable impact upon
latency and may even oversubscribe the WAN links. This could not only
cause problems for the Network Discovery process, but could also affect
any other applications that are communicating over these links.
In addition, restricting the devices that will be discovered to only core
devices will further reduce the traffic overheads of the Network Discovery
process, as any non-core devices will be discarded before 3Com Network
Director begins querying the devices for feature, configuration and
topology information. By limiting the subnets that are discovered to
important subnets only and by further restricting the discovery on those
subnets to particular IP address ranges you will reduce the traffic
overheads of the Network Discovery process and so decrease the
likelihood that it will have a noticeable impact upon the performance of
your WAN links.
Speeds up the Network Discovery process.
The length of time that it takes a Network Discovery to complete depends
upon various factors including the size of the subnets, or the ranges
within those subnets, that are being discovered, the number of devices
that are discovered on each subnet, the types of devices that are to be
discovered, the latency and reliability of the paths between 3Com
Network Director and the devices being discovered and the complexity of
the devices that are discovered.
By limiting the subnets that are discovered to important subnets only and
by further restricting the discovery on those subnets to particular IP
address ranges you can reduce the time it takes for the IP Ping stage of
Network Discovery and reduce the number of devices that will be queried
for feature, configuration and topology information. See "IP Ping " on
page 93 for more details of this Network Discovery stage.
In addition, restricting the devices that will be discovered to only core
devices may further reduce the number of devices that will be queried for
feature, configuration and topology information.