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A packet analyzer, also known as packet sniffer, protocol analyzer, or network analyzer, is a
computer program A computer program is a sequence or set of instructions in a programming language for a computer to execute. Computer programs are one component of software, which also includes documentation and other intangible components. A computer program ...
or
computer hardware Computer hardware includes the physical parts of a computer, such as the computer case, case, central processing unit (CPU), Random-access memory, random access memory (RAM), Computer monitor, monitor, Computer mouse, mouse, Computer keyboard, ...
such as a packet capture appliance, that can intercept and log traffic that passes over a
computer network A computer network is a set of computers sharing resources located on or provided by network nodes. The computers use common communication protocols over digital interconnections to communicate with each other. These interconnections are ...
or part of a network. Packet capture is the process of intercepting and logging traffic. As data streams flow across the network, the analyzer captures each packet and, if needed, decodes the packet's raw data, showing the values of various fields in the packet, and analyzes its content according to the appropriate
RFC RFC may refer to: Computing * Request for Comments, a memorandum on Internet standards * Request for change, change management * Remote Function Call, in SAP computer systems * Rhye's and Fall of Civilization, a modification for Sid Meier's Civ ...
or other specifications. A packet analyzer used for intercepting traffic on wireless networks is known as a wireless analyzer or WiFi analyzer. While a packet analyzer can also be referred to as a network analyzer or
protocol analyzer A protocol analyzer is a tool (hardware or software) used to capture and analyze signals and data traffic over a communication channel. Such a channel varies from a local computer bus to a satellite link, that provides a means of communication usi ...
these terms can also have other meanings. Protocol analyzer can technically be a broader, more general class that includes packet analyzers/sniffers. However, the terms are frequently used interchangeably.


Capabilities

On wired shared-medium networks, such as
Ethernet Ethernet () is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 198 ...
, Token Ring, and FDDI, depending on the network structure ( hub or switch), it may be possible to capture all traffic on the network from a single machine. On modern networks, traffic can be captured using a network switch using port mirroring, which mirrors all packets that pass through designated ports of the switch to another port, if the switch supports port mirroring. A
network tap A network tap is a system that monitors events on a local network. A tap is typically a dedicated hardware device, which provides a way to access the data flowing across a computer network. The network tap has (at least) three ports: an ''A port ...
is an even more reliable solution than to use a monitoring port since taps are less likely to drop packets during high traffic load. On
wireless LAN A wireless LAN (WLAN) is a wireless computer network A wireless network is a computer network that uses wireless data connections between network nodes. Wireless networking is a method by which homes, telecommunications networks and bus ...
s, traffic can be captured on one channel at a time, or by using multiple adapters, on several channels simultaneously. On wired broadcast and wireless LANs, to capture
unicast Unicast is data transmission from a single sender (red) to a single receiver (green). Other devices on the network (yellow) do not participate in the communication. In computer networking, unicast is a one-to-one transmission from one point in ...
traffic between other machines, the network adapter capturing the traffic must be in promiscuous mode. On wireless LANs, even if the adapter is in promiscuous mode, packets not for the service set the adapter is configured for are usually ignored. To see those packets, the adapter must be in
monitor mode Monitor or monitor may refer to: Places * Monitor, Alberta * Monitor, Indiana, town in the United States * Monitor, Kentucky * Monitor, Oregon, unincorporated community in the United States * Monitor, Washington * Monitor, Logan County, West Vi ...
. No special provisions are required to capture
multicast In computer networking, multicast is group communication where data transmission is addressed to a group of destination computers simultaneously. Multicast can be one-to-many or many-to-many distribution. Multicast should not be confused with ...
traffic to a multicast group the packet analyzer is already monitoring, or
broadcast Broadcasting is the distribution of audio or video content to a dispersed audience via any electronic mass communications medium, but typically one using the electromagnetic spectrum ( radio waves), in a one-to-many model. Broadcasting began ...
traffic. When traffic is captured, either the entire contents of packets or just the headers are recorded. Recording just headers reduces storage requirements, and avoids some privacy legal issues, yet often provides sufficient information to diagnose problems. Captured information is decoded from raw digital form into a human-readable format that lets engineers review exchanged information. Protocol analyzers vary in their abilities to display and analyze data. Some protocol analyzers can also generate traffic. These can act as protocol testers. Such testers generate protocol-correct traffic for functional testing, and may also have the ability to deliberately introduce errors to test the
device under test A device under test (DUT), also known as equipment under test (EUT) and unit under test (UUT), is a manufactured product undergoing testing, either at first manufacture or later during its life cycle as part of ongoing functional testing and calibra ...
's ability to handle errors. Protocol analyzers can also be hardware-based, either in probe format or, as is increasingly common, combined with a disk array. These devices record packets or packet headers to a disk array.


Uses

Packet analyzers can: * Analyze network problems * Detect
network intrusion A data breach is a security violation, in which sensitive, protected or confidential data is copied, transmitted, viewed, stolen or used by an individual unauthorized to do so. Other terms are unintentional information disclosure, data leak, info ...
attempts * Detect network misuse by internal and external users * Documenting regulatory compliance through logging all perimeter and endpoint traffic * Gain information for effecting a network intrusion * Identify data collection and sharing of software such as operating systems (for strengthening
privacy Privacy (, ) is the ability of an individual or group to seclude themselves or information about themselves, and thereby express themselves selectively. The domain of privacy partially overlaps with security, which can include the concepts of a ...
, control and security) * Aid in gathering information to isolate exploited systems * Monitor WAN bandwidth utilization * Monitor network usage (including internal and external users and systems) * Monitor data in transit * Monitor WAN and
endpoint security Endpoint security or endpoint protection is an approach to the protection of computer networks that are remotely bridged to client devices. The connection of endpoint devices such as laptops, tablets, mobile phones, Internet-of-things devices, ...
status * Gather and report network statistics * Identify suspect content in network traffic * Troubleshoot performance problems by monitoring network data from an application * Serve as the primary data source for day-to-day network monitoring and management * Spy on other network users and collect sensitive information such as login details or users cookies (depending on any content
encryption In cryptography, encryption is the process of encoding information. This process converts the original representation of the information, known as plaintext, into an alternative form known as ciphertext. Ideally, only authorized parties can decip ...
methods that may be in use) *
Reverse engineer Reverse engineering (also known as backwards engineering or back engineering) is a process or method through which one attempts to understand through deductive reasoning how a previously made device, process, system, or piece of software accompli ...
proprietary protocol In telecommunications, a proprietary protocol is a communications protocol owned by a single organization or individual. Intellectual property rights and enforcement Ownership by a single organization gives the owner the ability to place restricti ...
s used over the network * Debug client/server communications * Debug network protocol implementations * Verify adds, moves, and changes * Verify internal control system effectiveness ( firewalls, access control, Web filter, spam filter, proxy) Packet capture can be used to fulfill a warrant from a
law enforcement agency A law enforcement agency (LEA) is any government agency responsible for the enforcement of the laws. Jurisdiction LEAs which have their ability to apply their powers restricted in some way are said to operate within a jurisdiction. LEAs ...
to wiretap all network traffic generated by an individual.
Internet service provider An Internet service provider (ISP) is an organization that provides services for accessing, using, or participating in the Internet. ISPs can be organized in various forms, such as commercial, community-owned, non-profit, or otherwise private ...
s and
VoIP Voice over Internet Protocol (VoIP), also called IP telephony, is a method and group of technologies for the delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks, such as the Internet. The terms Internet t ...
providers in the United States must comply with Communications Assistance for Law Enforcement Act regulations. Using packet capture and storage, telecommunications carriers can provide the legally required secure and separate access to targeted network traffic and can use the same device for internal security purposes. Collecting data from a carrier system without a warrant is illegal due to laws about interception. By using end-to-end encryption, communications can be kept confidential from telecommunication carriers and legal authorities.


Notable packet analyzers

* Allegro Network Multimeter *
Capsa Gafsa ( aeb, ڨفصة '; ar, قفصة qafṣah), originally called Capsa in Latin, is the capital of Gafsa Governorate of Tunisia. It lends its Latin name to the Mesolithic Capsian culture. With a population of 111,170, Gafsa is the ninth-la ...
Network Analyzer * Charles Web Debugging Proxy *
Carnivore (software) Carnivore, later renamed DCS1000, was a system implemented by the Federal Bureau of Investigation (FBI) that was designed to monitor email and electronic communications. It used a customizable packet sniffer that could monitor all of a target user ...
*
CommView CommView is an application for network monitoring, packet analysis, and decoding. There are two editions of CommView: the standard edition for Ethernet networks and the wireless edition for 802.11 networks named CommView for WiFi. The application ...
*
dSniff dSniff is a set of password sniffing and network traffic analysis tools written by security researcher and startup founder Dug Song to parse different application protocols and extract relevant information. dsniff, filesnarf, mailsnarf, msgsnarf ...
* EndaceProbe Analytics Platform by Endace * ettercap *
Fiddler A fiddle is a Bow (music), bowed String instrument, string musical instrument, most often a violin. It is a colloquial term for the violin, used by players in all genres, including European classical music, classical music. Although in many ...
* Kismet *
Lanmeter A LANMeter was a tool for testing Token Ring and Ethernet computer network, networks introduced by Fluke Corporation in 1993. It incorporated hardware testing (Electrical cable, cable and network Network interface controller, interface card) and ...
*
Microsoft Network Monitor Microsoft Network Monitor is a Deprecation, deprecated packet analyzer. It enables capturing, viewing, and analyzing network data and deciphering network protocols. It can be used to troubleshoot computer network, network problems and applications ...
*
NarusInsight Narus Inc. was a Software industry, software company and Independent software vendor, vendor of big data analytics for cybersecurity. History In 1997, Ori Cohen, Vice President of Business and Technology Development for VDONet, founded Narus with ...
* NetScout Systems nGenius Infinistream *
ngrep ngrep (network grep) is a network packet analyzer written by Jordan Ritter. It has a command-line interface, and relies upon the pcap library and the GNU regex library. ngrep supports Berkeley Packet Filter ( BPF) logic to select network sources ...
, Network Grep *
OmniPeek Omnipeek is a packet analyzer software tool from Savvius, a LiveAction company, for network troubleshooting and protocol analysis. It supports an application programming interface (API) for plugins. History Savvius (formerly WildPackets) was ...
, Omnipliance by Savvius *
SkyGrabber SkyGrabber is a software from the Russian company ''SkySoftware'' which accepts input from a digital satellite tuner card for hard drive recording. History It was used by Iraqi insurgents from the group Kata'ib Hezbollah to intercept MQ-1 Predato ...
*The Sniffer * snoop * tcpdump * Observer Analyzer *
Wireshark Wireshark is a free and open-source packet analyzer. It is used for network troubleshooting, analysis, software and communications protocol development, and education. Originally named Ethereal, the project was renamed Wireshark in May 2006 d ...
(formerly known as Ethereal) * Xplico Open source Network Forensic Analysis Tool


See also

*
Bus analyzer A bus analyzer is a type of a protocol analysis tool, used for capturing and analyzing communication data across a specific interface bus, usually embedded in a hardware system. The bus analyzer functionality helps design, test and validation eng ...
*
Logic analyzer A logic analyzer is an electronic instrument that captures and displays multiple signals from a digital system or digital circuit. A logic analyzer may convert the captured data into timing diagrams, protocol decodes, state machine traces, a ...
*
Network detector Network detectors or network discovery software are computer programs that facilitate detection of wireless LANs using the 802.11b, 802.11a and 802.11g WLAN standards.''Wireless Hacking for Dummies''. Discovering networks may be done through acti ...
* pcap *
Signals intelligence Signals intelligence (SIGINT) is intelligence-gathering by interception of ''signals'', whether communications between people (communications intelligence—abbreviated to COMINT) or from electronic signals not directly used in communication ( ...
* Traffic generation model


Notes


References


External links

* {{Authority control Network analyzers Packets (information technology) Wireless networking Deep packet capture