Chapter 3. Overview

Net-Probe is primarily a graphical network monitor/tracking tool. Graphing, alarming and tracking functions make up the backbone of the features, and are built on a network layout diagram. Drawing tools have been kept as simple and productive as possible. Shortcuts to external programs are easy to integrate, making, for example, that SSH shell only two clicks away. High performance ping, traceroute, network scanning, SNMP browsing and DNS querying have been included. The ability to fix problems as they occur is offered through 'Failure Scripts'.

Five methods of obtaining data about the state of a network or network device is offered in Net-Probe. Simple Network Management Protocol (SNMP) is supported on virtually all network orientated devices (routers, printers, servers etc). All Unix boxes will have the ability to install this service. Microsoft server operating systems also offer this service. A lot of information can be obtained through this protocol and it is very useful for determining traffic loads and (in case of routers) determining the state of a network interface.

The second method is Microsoft's Performance monitor. This is offered by all Microsoft Operating Systems (NT, XP, 2000, 2003, 2008 and Vista). Also useful for determining network, service states and CPU loads.

The other methods of obtaining network information makes use of scripts and modules. These are small programs written to test or measure some aspect of a network or networked device. Tests for most of the standard services have been included with Net-Probe, so no scripting or programming skills are required. The more advanced networks will have specialized functions for which a standard check will not be sufficient. For these users, the ability to write a script in their favorite scripting language, to perform the test required, may be invaluable.

Scripts can be executed locally, on the computer which has Net-Probe installed, or remotely, on some other computer. The reason for remote execution is that some tests may only be able to measure a parameter of the computer they are being run on. Supporting programs called 'NetProbe-Remote.pl' or 'NetProbe-Remote-Service' (part of the Net-Probe package) will have to be installed on the remote computers for this remote execution to work. 'Remote-Probe.pl' is a Perl Script so it should be usable on most operating systems (almost all operating systems are supported by Perl). NetProbe-Remote-Service is a service for Windows operating systems. Net-Probe will pass the required script to the remote computer with the help of NetProbe-Remote. NetProbe-Remote will then execute the script at the required times and transfer the data back to Net-Probe for graphing and for alarming.

The ability to execute a test on a different computer also offers the ability to measure/test a parameter from a different perspective on the network. Depending on the type of function being tested, it is possible that the test will pass from one host's perspective but fail from another. Some services may only be accessible from a given host due to access lists, so testing from the right host may be essential.

Scripts have been written, for the most part, in both VB-Script and Perl-Script. A few of the more specialized tests are only present in Perl-Script. VB-Script has been chosen because if Net-Probe installs on the computer, the VB-Script engine will be installed. Perl-Script has been chosen for two reasons. First, almost all operating systems are supported by Perl, and Perl has lots of network based modules already written, unlike most other scripting languages. This means that if you need some specialized test, Perl will most lightly offer the best starting point and the fastest rate of development.

'Remote-Probe.pl', being written in Perl, will work on most operating systems. As already mentioned it executes scripts sent to it by Net-Probe and returns the results to Net-Probe. If 'Remote-Probe.pl' were installed on a Linux box it would not make any sense to send it a VB-Script to execute, as most Linux boxes cannot execute a VB-Script. But almost all can execute a Perl Script.

The RemoteCE program offers the ability to get GPS information from a Windows CE device and to send the location information back to Net-Probe. The location of the device can then be plotted and tracked. If a team of mobile engineers were to be empowered with a device like the HP iPAQ PDA, the location of the team could be tracked. This information would enable the team to be optimally utilized, by minimizing transport expenses and maximizing onsite time.

Figure 3.1. Net-Probe - Network

Net-Probe - Network

Figure 3.2. Net-Probe - World Map

Net-Probe - World Map

Figure 3.3. Net-Probe - Tracker

Net-Probe - Tracker

Copyright (c) Warren Flemmer 2006www.net-probe.com