Editing Packet analyzer

{{Short description|Computer network equipment or software that analyzes network traffic}}
{{Use mdy dates|date=December 2020}}
{{Use American English|date=March 2015}}

[[File:Wireshark 3.6 screenshot.png|thumb|Screenshot of Wireshark network protocol analyzer]]

A '''packet analyzer''' (also '''packet sniffer''' or '''network analyzer''')<ref name="Chapple2018">{{cite book |last1=Chapple |first1=Mike |last2=Stewart |first2=James Michael |last3=Gibson |first3=Darril |title=(ISC)2 CISSP Certified Information Systems Security Professional Official Study Guide |date=2018 |publisher=John Wiley & Sons |isbn=978-1-119-47587-3 |url=https://books.google.com/books?id=psJVDwAAQBAJ&pg=PA647 |language=en |quote=A sniffer (also called a packet analyzer or protocol analyzer) is a software application that captures traffic traveling over the network. |access-date=March 23, 2023 |archive-date=April 5, 2023 |archive-url=https://web.archive.org/web/20230405072609/https://books.google.com/books?id=psJVDwAAQBAJ&pg=PA647 |url-status=live }}</ref><ref name="Rakibul2020">{{cite book |last1=Rakibul |first1=Hoque, Md |last2=Edward |first2=Bashaw, R. |title=Cross-Border E-Commerce Marketing and Management |date=2020 |publisher=IGI Global |isbn=978-1-7998-5824-9 |page=186 |url=https://books.google.com/books?id=xrkIEAAAQBAJ&pg=PA186 |quote=Packet Sniffing: It is also known as packet analyzer, protocol analyzer |access-date=March 23, 2023 |archive-date=April 5, 2023 |archive-url=https://web.archive.org/web/20230405180903/https://books.google.com/books?id=xrkIEAAAQBAJ&pg=PA186 |url-status=live }}</ref><ref name="Trost2009">{{cite book |last1=Trost |first1=Ryan |title=Practical Intrusion Analysis: Prevention and Detection for the Twenty-First Century: Prevention and Detection for the Twenty-First Century |date=2009 |publisher=Pearson Education |isbn=978-0-321-59188-3 |url=https://books.google.com/books?id=3y2fhCaJJA0C&pg=PT59 |quote=A packet sniffer (also known as a packet analyzer, protocol analyzer, or networkanalyzer) monitors network traffic |access-date=March 23, 2023 |archive-date=April 5, 2023 |archive-url=https://web.archive.org/web/20230405072610/https://books.google.com/books?id=3y2fhCaJJA0C&pg=PT59 |url-status=live }}</ref><ref>{{cite book |last1= |first1= |title=Cyber Law, Privacy, and Security: Concepts, Methodologies, Tools, and Applications |date=2019 |publisher=IGI Global |isbn=978-1-5225-8898-6 |page=58 |url=https://books.google.com/books?id=OpGbDwAAQBAJ&pg=PA58 |quote=Packet Sniffing: A packet analyzer, also called as a network analyzer, protocol analyzer or packet sniffer |access-date=March 23, 2023 |archive-date=April 6, 2023 |archive-url=https://web.archive.org/web/20230406043813/https://books.google.com/books?id=OpGbDwAAQBAJ&pg=PA58 |url-status=live }}</ref><ref name="Asrodia2012">{{cite journal |last1=Asrodia |first1=Pallavi |last2=Patel |first2=Hemlata |title=Analysis of Various Packet Sniffing Tools for Network Monitoring and Analysis |journal=International Journal of Electrical, Electronics and Computer Engineering |date=2012 |page=55 |citeseerx=10.1.1.429.567 |issn=2277-2626 |quote=Packet Sniffing... also known as Network or Protocol Analyzer or Ethernet Sniffer}}</ref><ref name="kaspersky2018">{{cite web |title=What is a Packet Sniffer? |url=https://www.kaspersky.com/resource-center/definitions/what-is-a-packet-sniffer |website=www.kaspersky.com |date=2018 |access-date=December 26, 2021 |archive-date=August 30, 2023 |archive-url=https://web.archive.org/web/20230830125455/https://www.kaspersky.com/resource-center/definitions/what-is-a-packet-sniffer |url-status=live }}</ref><ref name="Endace2023">{{cite web |title=What is Network Packet Capture? |url=https://www.endace.com/learn/what-is-network-packet-capture |website=www.endace.com |date=2023 |access-date=April 5, 2023 |archive-date=July 30, 2023 |archive-url=https://web.archive.org/web/20230730185317/https://www.endace.com/learn/what-is-network-packet-capture |url-status=live }}</ref><ref name="PcMag">{{cite web |title=Definition of network analyzer |url=https://www.pcmag.com/encyclopedia/term/network-analyzer |website=PCMAG |access-date=December 26, 2021 |archive-date=April 5, 2023 |archive-url=https://web.archive.org/web/20230405180906/https://www.pcmag.com/encyclopedia/term/network-analyzer |url-status=live }}</ref> is a [[computer program]] or [[computer hardware]] such as a [[packet capture appliance]] that can [[Traffic analysis|analyze]] and [[Logging (computing)|log]] traffic that passes over a [[computer network]] or part of a network.<ref>{{cite book|title=Law of Internet Security and Privacy|author=Kevin J. Connolly|pages=131|year=2003|isbn=978-0-7355-4273-0|publisher=[[Aspen Publishers]]}}</ref> '''Packet capture''' is the process of intercepting and logging traffic. As [[data stream]]s flow across the network, the analyzer captures each [[Network packet|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 [[Request for Comments|RFC]] or other specifications.

A packet analyzer used for intercepting traffic on wireless networks is known as a '''wireless analyzer''' - those designed specifically for [[Wi-Fi]] networks are '''Wi-Fi analyzers'''.{{efn|The term Wi-Fi analyzer is also used to describe the instruments/software for [[wireless site survey]]s.}} While a packet analyzer can also be referred to as a [[Network analyzer (disambiguation)|network analyzer]] or [[protocol analyzer]] these terms can also have other meanings. Protocol analyzer can technically be a broader, more general class that includes packet analyzers/sniffers.<ref>{{cite journal |last1=Sikos |first1=Leslie F. |title=Packet analysis for network forensics: A comprehensive survey |journal=Forensic Science International: Digital Investigation |date=2020 |volume=32 |page=200892 |doi=10.1016/j.fsidi.2019.200892 |s2cid=212863330 |issn=2666-2817 |quote=Those protocol analyzers that are designed for packet analysis are called packet analyzers (packet sniffers, sometimes network analyzers).|doi-access=free }}</ref> However, the terms are frequently used interchangeably.<ref>{{cite book |last1=Poulton |first1=Don |title=MCTS 70-642 Cert Guide: Windows Server 2008 Network Infrastructure, Configuring |date=2012 |publisher=Pearson Education |isbn=978-0-13-280216-1 |url=https://books.google.com/books?id=VQuWAAAAQBAJ&pg=PT1267 |quote=protocol analyzer. Also known as a network analyzer or packet analyzer, a protocol analyzer is a hardware device or software program that enables you to capture, store, and analyze each packet that crosses your network |access-date=March 23, 2023 |archive-date=April 13, 2023 |archive-url=https://web.archive.org/web/20230413100037/https://books.google.com/books?id=VQuWAAAAQBAJ&pg=PT1267 |url-status=live }}</ref>

==Capabilities==
On wired [[shared-medium network]]s, such as [[Ethernet]], [[Token Ring]], and [[FDDI]], depending on the network structure ([[Ethernet hub|hub]] or [[network switch|switch]]),<ref>{{Cite web |title = Network Segment Definition |url = http://www.linfo.org/network_segment.html |website = www.linfo.org |access-date = January 14, 2016 |archive-date = June 7, 2023 |archive-url = https://web.archive.org/web/20230607181215/http://www.linfo.org/network_segment.html |url-status = live }}</ref>{{efn|Some methods avoid traffic narrowing by switches to gain access to traffic from other systems on the network (e.g., [[ARP spoofing]]).}} 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]] 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]]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]] 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 (802.11 network)|service set]] the adapter is configured for are usually ignored. To see those packets, the adapter must be in [[monitor mode]].{{Citation needed|date=January 2012}} No special provisions are required to capture [[multicast]] traffic to a multicast group the packet analyzer is already monitoring, or [[Broadcasting (networking)|broadcast]] traffic.

When traffic is captured, either the entire contents of packets or just the [[header (computing)|header]]s are recorded. Recording just headers reduces storage requirements, and avoids some [[Privacy law|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]]'s ability to handle errors.<ref>{{Cite web |title=Lab Protocol Analyzers |url=https://www.amilabs.com/labanalyzers.htm |access-date=2023-06-30 |website=www.amilabs.com |archive-date=June 30, 2023 |archive-url=https://web.archive.org/web/20230630023940/https://www.amilabs.com/labanalyzers.htm |url-status=live }}</ref><ref>{{Cite web |last=shivakumar |date=2020-12-18 |title=Where is Protocol analyzer used? |url=https://prodigytechno.com/where-protocol-analyzer-is-used/ |access-date=2023-06-30 |website=Prodigy Technovations |language=en-US |archive-date=June 30, 2023 |archive-url=https://web.archive.org/web/20230630025446/https://prodigytechno.com/where-protocol-analyzer-is-used/ |url-status=live }}</ref>

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 detection system|network intrusion]] 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]], 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]] 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]] methods that may be in use)
* [[Reverse engineer]] [[proprietary protocol]]s used over the network
* Debug [[Client–server model|client/server communications]]
* Debug network protocol implementations
* Verify adds, moves, and changes
* Verify internal control system effectiveness ([[Firewall (computing)|firewalls]], access control, Web filter, spam filter, proxy)

Packet capture can be used to fulfill a warrant from a [[law enforcement agency]] to [[wiretap]] all network traffic generated by an individual. [[Internet service provider]]s and [[VoIP]] 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.<!--[[User:Kvng/RTH]]-->

==Notable packet analyzers==
{{Main list|Comparison of packet analyzers}}
{{div col|colwidth=20em}}
* Allegro Network Multimeter
*[[Capsa (software)|Capsa]] Network Analyzer
*[[Charles Proxy|Charles Web Debugging Proxy]]
*[[Carnivore (software)]]
*[[CommView]]
*[[dSniff]]
*[[Endace|EndaceProbe Packet Capture Platform]]
*[[Ettercap (software)|ettercap]]
*[[Fiddler (software)|Fiddler]]
*[[Kismet (software)|Kismet]]
*[[Lanmeter]]
*[[Microsoft Network Monitor]]
*[[NarusInsight]]
*[[NetScout Systems|NetScout Systems nGenius Infinistream]]
*[[ngrep]], Network Grep
*[[OmniPeek]], Omnipliance by Savvius
*[[SkyGrabber]]
*The [[Sniffer (protocol analyzer)|Sniffer]]
*[[snoop (software)|snoop]]
*[[tcpdump]]
*[[Viavi Solutions#Service Enablement (SE)|Observer Analyzer]]
*[[Wireshark]] (formerly known as Ethereal)
*[[Xplico]] Open source Network Forensic Analysis Tool
{{div col end}}

==See also==
*[[Bus analyzer]]
*[[Logic analyzer]]
*[[Network detector]]
*[[pcap]]
*[[Signals intelligence]]
*[[Traffic generation model]]

==Notes==
{{notelist}}

==References==
{{reflist}}

==External links==
{{Commons category|Computer data network analyzers}}
{{Wikiversity | Packet analyzer}}
* [https://www.endace.com/learn/what-is-network-packet-capture Packet Capture]

{{Authority control}}

[[Category:Network analyzers]]
[[Category:Packets (information technology)]]
[[Category:Wireless networking]]
[[Category:Deep packet capture]]