Hello Jeremy,
Discovering a network totally depends on the factor from where you are
discovering it i.e. within the network (inside) or outside the network.
Off-course discovering network from within the network is far more accurate as
compared to the external ones.
If you are absolutely sure that all the computers within the network are
utilizing Microsoft Windows OS, then a tool called MBSA with Visio connector
from Microsoft, could help you out in discovering the network topology
(provided you have Microsoft Visio installed on your system). However third
party tools like GFI Languard, Superscan or any network security scanner, can
also help easily to discover the network. Off-course Nmap has always been an
indispensable tool for network discovery.
Now-a-days scanners and discovery tools are so sophisticated and accurate that
we can rely on the outputs of these tools without much hesitation. This is
because the rate of false-positive outputs from these tools has been reduced
drastically. However for our satisfactions, we could just verify by ourselves
that the outputs are correct and are not false positives, by manually doing
telnet to the IP Address and port.
Besides traceroute (Windows tracert), Windows XP and above OS supports a
built-in command called pathping which is basically an integration of two
commands: tracert and ping. The advantages of pathping over ping and tracert
are that each node is pinged as the result of a single command, and that the
behaviour of nodes is studied over an extended time period, rather than the
Ping's default sample of four messages or tracert's default single route trace.
Reference:
MBSA with Visio Connector:
http://www.microsoft.com/technet/security/tools/mbsavisio.mspx
GFI Languard: http://www.gfi.com/lannetscan/
SuperScan:
http://www.foundstone.com/index.htm?subnav=resources/navigation.htm&subcontent=/resources/proddesc/superscan.htm
Nikhil Wagholikar
Security Analyst
NII Consulting
Web: www.niiconsulting.com
