What Is Port Sniffing?

Most computers are connected to networks of telecommunication devices. These networks allow computers to communicate with each other over ports of communication. Port sniffing is a process of reading and interpreting data that is transferred on a specific network communication port. This process is a useful tool for verifying and validating data between computers.

It is important to perform port sniffing operations on newly developed software. This is a good method of validating data accuracy, volume, and consistency throughout a software application. Port sniffing software allows a testing team to view the data that is transmitted over a network device.

Security analysts typically rely on port sniffing programs to determine software vulnerabilities. These analysts must inspect software applications for proper encryption and potential unwanted data exposure. Sniffing tools give them a method determining if critical information is passed over a public network. This information includes passwords, systems identification, and port addresses. If this data is sent unencrypted it could be potentially harmful for an organization.

Port sniffing is also available on many network monitoring software programs. This real-time port sniffing provides a view into the type of messages transmitted throughout a network. A sniffing program is an good tool for reviewing data that is transferred in and out of an organization.


When data is transmitted over a network it is typically split in the form of data packets. This process is performed to throttle messages to support network capacity. Each packet is sent over the network as an individual unit. Once it arrives on the receiving computer it is reassembled into a full message.

Packet sniffing is another form of port sniffing that verifies the size of information that is transmitted within a network. This is a good tool for capturing and analyzing the content of data based on predefined parameters for packets. Packet sniffing allows a detailed view of network monitoring and bandwidth usage analysis.

Sniffing programs can also read and interpret all types of ports. This includes USB, serial, and standard ethernet ports. These programs provide a means of troubleshooting issues between applications and external hardware devices.

This type of program can be used as a diagnostic tool. In the event of a hardware failure, a systems engineer can use port sniffing programs to determine the exact issues between devices. The software can read the data that is transmitted to a device. This provides valuable data to the engineer that can be used to determine where the failure is occurring. This information includes data speed, configuration, protocol, and format.

What Is Network Sniffing?

Network sniffing is a method of using specialized hardware and software to access information that isn’t being sent to someone or analyzing networks to which individuals don’t have legitimate access. Most sniffers work by analyzing data packets. Depending on which type of network sniffing is being used, the sniffer can read these packets both inside and outside a network. While network sniffing does have several legitimate uses, it is generally associated with the hacking community.

After information is sent over a network, it is broken up into packets. These packets contain a small amount of the information, the addresses of the receiver and sender and some technical data. Specialized hardware or software can intercept and copy these packets. Once she has a copy, a user is able to open the packet and read the information and addresses.

When done from inside a network, this is usually an internal security and troubleshooting method. System administrators will randomly monitor packets to make sure that the intended addressee is not attempting to circumvent Internet security protocols or access blocked locations. With this form of network sniffing, typically only the addresses are read.

If used as an internal network troubleshooting method, packets are analyzed in streams, often from across an entire network switch. Packets are checked for degradation in data or missing sequences. If there are any problems, then the network likely has a faulty piece of hardware. Additional locations are tested using similar methods until the faulty piece is found.

What Are WiFi® Sniffers?

Although many people like to rely on their laptop computer to detect available wireless networks at a particular location, devices known as WiFi sniffers were created specifically to capture this information. The basic premise being that before someone goes to the trouble of starting up their computer, they can verify that there is indeed a compatible and available wireless broadband network in the area.

WiFi sniffers are available both as stand-alone, hard-top items and as software add-on applications for a person's portable wireless devices. Many of these add-on applications for smartphones and PDAs are free of charge; as the penetration of portable wireless devices has increased, it has rendered hard-top WiFi sniffers obsolete for all but the most specialized of IT personnel.

Some companies have banned WiFi sniffer software and applications that have the capability to randomly scan for available networks. These plug-ins, also known as stumblers, were removed in favor of authorized directory-based applications. Both free and fee-based directory applications and plug-ins are commonly available.

In today's ultra-competitive, user-review driven Internet environment, much online discussion is now focused on which of these add-on WiFi sniffers are the best at doing the sniffing. WiFi sniffer reviews are readily available on online tech websites and social media platforms; users are quick to share their opinion about an add-on's effectiveness as soon as they have tried it.

What Is IP Sniffing?

Internet Protocol (IP) sniffing refers to analyzing the traffic on a network. This can be limited to analyzing the traffic coming from a single computer on the network or to every computer on the network. IP sniffing intercepts packets of information on the network. This method can be used for a variety of different things.

IP sniffing can be used to detect possible intrusions on the network. By analyzing the traffic on the network, a user can detect whether or not an unauthorized user has attempted to gain access. This method can also be used for determining if authorized users on the network have been violating the network terms of use.

Other uses for IP sniffing programs involve filtering out certain types of content and connections from the network. This can be used to increase the security of a network or to limit users' access to certain types of content. Network administrators may use these programs to block connections to instant messaging services or specific websites.

IP sniffing can also be used by malicious users to steal information from other users. By intercepting network traffic, a malicious user can analyze the packets of information sent to websites. This can result in a user's account security being compromised.

Preventing WiFi Sniffing

To protect a WLAN from WiFi sniffing, useful steps including changing the default administration password for the access point, such as a router, and making sure the firmware is up-to-date. One should also change the SSID (Service Set Identifier) name of the router, which is the public name and usually comes with a brand name as its default. Using network encryption and choosing Wi-Fi Protected Access (WPA), rather than Wired Equivalent Privacy (WEP), for encrypting are also good steps as well as using Secure Sockets Layer (SSL) encryption for browsing.

Packet Sniffing

The terms WiFi sniffing and packet sniffing are sometimes used interchangeably, but packet sniffing does not refer to locating WiFi networks, only to monitoring activity on them. The sort of WiFi sniffing that can also be called packet sniffing is used by network administrators to find faults in a network so they can be plugged. This kind of sniffing identifies the packets of data that are being transmitted from or received by the network. The name of the tool for this job is a network analyzer when used by an authorized person, but is more likely to be called a packet sniffer when used by a thief to capture and decode other people’s data. Illegally gaining access to these packets is very similar to wire-tapping.

How It's Done

WiFi sniffing to locate viable networks can be legitimately used for activities like searching an unfamiliar urban area for a wireless hotspot. This can be done with an electronic device or with software; the same device can be used to detect and steal WiFi from a homeowner who has it activated in their home. When used with ill intent from a moving vehicle, this practice is sometimes referred to as wardriving. Apple removed all WiFi sniffing software from its App Store in March of 2010, but the iPhone has a built-in WiFi scanning feature to locate wireless hotspots.