NBScan is a NetBIOS Scanner, a
powerful and fast tool for exploring networks. NBScan can scan a
network within a given range of IP addresses and list computers
offering NetBIOS resource sharing service as well as their name
tables. Unlike the nbtstat utility supplied with Windows, this tool
provides a friendly, graphical, user interface and easy management
of the lmhosts file and features parallel scanning, which allows
checking a class C network in less than 1 minute. Both Class C and
B networks can be scanned. NBScan can facilitate routine tasks
often carried out by system integrators, administrators, and
Before you start scanning, you
should enter the starting and ending IP addresses in the
IP fields as shown
above. You may also want to specify the number of simultaneous
connections and the connection timeout in the Tasks
fields. You can sometimes
enable the Advanced Mode
(see the description below).
to begin scanning.
When NBScan detects a computer
that offers NetBIOS resource sharing within the set range, the
information about the computer is added to the list. The
address columns are
self-explanatory. The RS, or Resource
column, is used to assess
whether the computer offers resource sharing: Some computers may
not be configured to share resources; however, they respond to
NetBIOS queries and are listed.
Left-clicking on a listed
computer displays its name table in the lower window. If you have a
problem interpreting name tables, you can take a look at the
reference included in this help file.
Right-clicking on a listed
computer brings up a menu with the following commands:
– attempts to open the selected
computer. If the computer is accessible, a new Windows Explorer
window with remote resources will appear.
||Add Item to
LMHosts - adds a record
associated with the selected computer to the lmhosts file in the
||Add All Items to
LMHosts - adds records
associated with the listed computers to the lmhosts file in the
appropriate format (computers that have no shared resources are not
||Copy IP Address
– copies the selected
computer's IP address to the clipboard.
||Copy MAC Address
– copies the selected
computer's MAC address to the clipboard.
– sends the selected IP address
to other tools or to SmartWhois.
– copies the NBScan table to
||Save – saves the NBScan table to a
Because of some peculiarities
in handling NetBIOS connections, a small percentage of computers
can send replies to queries only to port 137, no matter from which
port the query was sent. The advanced mode allows you to choose
whether you want the program to receive replies sent to port 137.
To switch to the advanced mode, select the Advanced
to local port 137) box.
The advanced mode may not be available if the computer has logged
on to the network. If the computer has already logged on, this menu
item is disabled. If you want to use this mode, you should turn it
on BEFORE logging on to the network. For example, if you use a
dial-up connection to the Internet, you should first launch the
program, and then check Advanced mode (bind to
local port 137), and
Using the advanced mode can influence the operation of some of the
Windows network services bound to port 137, e.g. you might not be
able to use nbtstat or connect to remote computers. In order to
restore the normal operation of such services, you should turn off
the advanced mode, log off the network, and log on again.
The reason for these
limitations is simple: There is only one port 137 on any system,
and it is "owned" by the process that claimed the port first. If
Essential NetTools was the first to bind to this port, the program
can operate in the advanced mode, but the OS is unable to use it.
If the OS binds to it first, then Essential NetTools cannot use the
same port. Please remember that this mode is just an advanced
feature, and you may not need to use it. In fact, it's quite
probable that you will not notice any difference between the
results obtained with the advanced mode turned on or off.