Ip Ping; Device Capability Detection - 3Com 3C15500 - Network Director User Manual

9 Device Sizing
With the exception of the sizing stage (explained below), each of the
stages runs sequentially, and the sequence is repeated for each subnet
that is being discovered. The sizing stage runs once only, when all the
other stages have been executed for all of the subnets being discovered.
The purpose of each stage is described below:

IP Ping

In order to detect which IP nodes exist, this stage performs an IP Ping over
the specified ranges of addresses for the subnet. If no ranges are
specified, a default range is deduced from the subnet address and subnet
mask of the subnet being discovered. This range excludes the subnet
address itself (lowest address value) and the subnet broadcast address
(highest address value).

Device Capability Detection

This stage is applied to each device that responded to a ping in the
previous stage. Its purpose is to determine if a device supports certain
network protocols. Specifically, these are:
SNMP
HTTP
Telnet
The most detailed information is generally obtained from devices that
support SNMP. For these devices 3Com Network Director initially starts
the communication using the read community string as originally
specified in the Network Discovery wizard. Having successfully
communicated using the read community string it then attempts
communication using the write community string(s), again obtained from
the Network Discovery wizard. While the write community string is not
heavily used by the discovery process (except a small part of topology), it
is used extensively by other features of 3Com Network Director.
Consequently, if the write community cannot be successfully determined,
discovery will continue, but add a warning to the report provided at the
end of discovery.
3Com Network Director detects HTTP and Telnet capabilities by
attempting to open a TCP connection to the device using ports 80 and 23
respectively. The purpose of this detection is to decide whether to enable
Key Concepts 93