Generating a Network Map with Various Tools

A network map permits an analysis of the physical connections of a computer network and the various components within that network, such as network transport devices and servers. This map has several applications that are beneficial for an organization, such as monitoring, analyzing, and troubleshooting.

For example, a map of the network may be used to assist IT pros in finding any bottlenecks or single points of failure. Network diagram software is often used to draw a logical - and sometimes physical - diagram of the network for easier visualization. This diagram comes in very handy in proving compliance with regulations, managing the many components within your network more efficiently, and in speeding up network troubleshooting.

Depending on the complexity of your network diagram software, a network map can have a variety of features. It can show the physical configuration of the network and elaborate logical perspectives of the computer network. Labels can be added to devices, indicating the computer name, serial number, IP address, manufacturer, and other attributes that will assist in tracking down problem devices. Specific data pertaining to your firewalls, switches and routers will typically be provided via Simple Network Management Protocol, or SNMP. With precise documentation, network administrators may be able to prove abidance to certain standards, such as the Health Insurance Portability and Accountability Act (HIPAA) or the Payment Card Industry Data Security Standard (PCIDSS).

The software may also include a way to map network drives for more detailed information that administrators might want to use for planning or troubleshooting purposes. A network sniffer component, for instance, may also be bundled in the software package to enable network managers to monitor and capture data. Network sniffers analyze the data or network traffic and usually create a copy of the data without making any changes or altering its route so it's completely unobtrusive. Such a program serves a number of functions and has a variety of applications, including:

* checking network usage
* observing if there are any attempts to intrude into the network (by setting filters and alters)
* troubleshooting
* debugging network communications issues by analyzing your IP packets
* collecting statistics.

However, a network sniffer typically does not have the ability to filter out specific network traffic that may be harmful to the system. A sniffer is typically used as an analysis tool.

However, a network sniffer may also have a number of undesirable uses in the wrong hands, primarily network intrusion and hacking. A potentially dangerous capability of this tool is that it can be used to gather confidential information, including passwords, user names, email content, web pages that have been visited, and others. This is accomplished by capturing data copies passing through your network. Upon capturing data, one could use the gathered information to change the direction of network traffic through techniques such as issuing fake Address Resolution Protocol (ARP) responses or terminating ongoing TCP connections.

Another potential capability of these tools is network discovery or network detection. This feature allows the detection of other networks or network devices that can be reached from within your network, such as wireless LANs. This may be performed through active or passive scanning.

The process of active scanning is performed by transmitting several probe requests and then listening for any replies. The disadvantage of this method is that it won't be able to detect a network where broadcasting of Service Set Identifiers (SSID) has been disabled. In passive scanning, the technique is to listen for data that is transmitted by the Access Point (AP). Once an authorized user makes a connection to the AP, the AP will transmit an SSID that the tool uses to present itself as an authorized user.