{"id":278,"date":"2009-08-06T19:56:56","date_gmt":"1999-01-01T00:00:00","guid":{"rendered":"https:\/\/fir3netwp.gmsrrpobkbd.com\/?p=278"},"modified":"2021-07-27T17:55:18","modified_gmt":"2021-07-27T17:55:18","slug":"tcp-flags","status":"publish","type":"post","link":"https:\/\/www.fir3net.com\/uncategorized\/tcp-flags.html","title":{"rendered":"TCP Flags Definition and Operation"},"content":{"rendered":"<p>&nbsp;<\/p>\n<ul>\n<li><span class=\"docEmphStrong\">URG<\/span> This flag indicates that the packet contains urgent data that should be processed as soon as possible. This flag is used to provide two virtual channels within one TCP connection. The URG flag is also known as <span class=\"docEmphasis\">out-of-band<\/span>. This is usefful for a sender to present data that can overtake any bytes queued in the send and recieve buffers and be presented directy to the receiving application . For example, in Telnet the interrrupt key sequenece may be pressed and sent to overtake all other traffic and enable the recievd whatever it is doing with the received data.<\/li>\n<\/ul>\n<ul>\n<li>\n<p class=\"docText\"><span class=\"docEmphStrong\">ACK<\/span> This flag indicates that the packet is an acknowledgement for a previous packet. It is always set for normal data flow once a connection is established. The ACK bit is also sometimes called the <span class=\"docEmphasis\">established<\/span> bit.<\/p>\n<\/li>\n<li>\n<p class=\"docText\"><span class=\"docEmphStrong\">PSH<\/span> This flag, or push bit, tells the operating system to transmit the data at once; the receiving end should also transmit the data to the application right away. If this flag is not set, the operating system is free to buffer TCP transmissions to optimally manage the data.<\/p>\n<\/li>\n<li>\n<p class=\"docText\"><span class=\"docEmphStrong\">RST<\/span> This flag resets the TCP connection when an error occurs. Errors can include an incomplete initial handshake, a timeout at another phase of the connection, or a SYN sent to a port that isn&#8217;t listening or is filtering connections.<\/p>\n<\/li>\n<li>\n<p class=\"docText\"><span class=\"docEmphStrong\">SYN<\/span> This flag sets the initial request to synchronize sequence numbers and is used to initiate a connection between two hosts.<\/p>\n<\/li>\n<li>\n<p class=\"docText\"><span class=\"docEmphStrong\">FIN<\/span> This flag is used to gracefully disconnect an existing session, notifying the remote system that there will be no more transmissions.<\/p>\n<\/li>\n<li>When a receiving TCP sees the PUSH flag, it must not wait for more data from the sending TCP before passing the data to the receiving process.<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>&nbsp; URG This flag indicates that the packet contains urgent data that should be processed as soon as possible. This flag is used to provide two virtual channels within one TCP connection. The URG flag is also known as out-of-band. This is usefful for a sender to present data that can overtake any bytes queued &#8230; <a title=\"TCP Flags Definition and Operation\" class=\"read-more\" href=\"https:\/\/www.fir3net.com\/uncategorized\/tcp-flags.html\" aria-label=\"Read more about TCP Flags Definition and Operation\">Read more<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[13],"tags":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v22.5 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>TCP Flags Definition and Operation - Fir3net<\/title>\n<meta name=\"description\" content=\"&nbsp; URG This flag indicates that the packet contains urgent data that should be processed as soon as possible. This flag is used to provide two virtual\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.fir3net.com\/uncategorized\/tcp-flags.html\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"TCP Flags Definition and Operation - Fir3net\" \/>\n<meta property=\"og:description\" content=\"&nbsp; URG This flag indicates that the packet contains urgent data that should be processed as soon as possible. This flag is used to provide two virtual\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.fir3net.com\/uncategorized\/tcp-flags.html\" \/>\n<meta property=\"og:site_name\" content=\"Fir3net\" \/>\n<meta property=\"article:published_time\" content=\"1999-01-01T00:00:00+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2021-07-27T17:55:18+00:00\" \/>\n<meta name=\"author\" content=\"Rick Donato\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"Rick Donato\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"1 minute\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\/\/www.fir3net.com\/uncategorized\/tcp-flags.html#article\",\"isPartOf\":{\"@id\":\"https:\/\/www.fir3net.com\/uncategorized\/tcp-flags.html\"},\"author\":{\"name\":\"Rick Donato\",\"@id\":\"https:\/\/www.fir3net.com\/#\/schema\/person\/ab35009601b7687ee1c5310be6038037\"},\"headline\":\"TCP Flags Definition and Operation\",\"datePublished\":\"1999-01-01T00:00:00+00:00\",\"dateModified\":\"2021-07-27T17:55:18+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\/\/www.fir3net.com\/uncategorized\/tcp-flags.html\"},\"wordCount\":302,\"publisher\":{\"@id\":\"https:\/\/www.fir3net.com\/#organization\"},\"articleSection\":[\"Networking Concepts\"],\"inLanguage\":\"en-US\"},{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.fir3net.com\/uncategorized\/tcp-flags.html\",\"url\":\"https:\/\/www.fir3net.com\/uncategorized\/tcp-flags.html\",\"name\":\"TCP Flags Definition and Operation - Fir3net\",\"isPartOf\":{\"@id\":\"https:\/\/www.fir3net.com\/#website\"},\"datePublished\":\"1999-01-01T00:00:00+00:00\",\"dateModified\":\"2021-07-27T17:55:18+00:00\",\"description\":\"&nbsp; URG This flag indicates that the packet contains urgent data that should be processed as soon as possible. This flag is used to provide two virtual\",\"breadcrumb\":{\"@id\":\"https:\/\/www.fir3net.com\/uncategorized\/tcp-flags.html#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/www.fir3net.com\/uncategorized\/tcp-flags.html\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/www.fir3net.com\/uncategorized\/tcp-flags.html#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/www.fir3net.com\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Networking\",\"item\":\"https:\/\/www.fir3net.com\/networking\"},{\"@type\":\"ListItem\",\"position\":3,\"name\":\"Networking Concepts\",\"item\":\"https:\/\/www.fir3net.com\/networking\/concepts-networking\"},{\"@type\":\"ListItem\",\"position\":4,\"name\":\"TCP Flags Definition and Operation\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/www.fir3net.com\/#website\",\"url\":\"https:\/\/www.fir3net.com\/\",\"name\":\"Fir3net\",\"description\":\"Keeping you in the know\",\"publisher\":{\"@id\":\"https:\/\/www.fir3net.com\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/www.fir3net.com\/?s={search_term_string}\"},\"query-input\":\"required name=search_term_string\"}],\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\/\/www.fir3net.com\/#organization\",\"name\":\"Fir3net\",\"url\":\"https:\/\/www.fir3net.com\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/www.fir3net.com\/#\/schema\/logo\/image\/\",\"url\":\"https:\/\/www.fir3net.com\/wp-content\/uploads\/Fir3net-Background-Logo-compressed.png\",\"contentUrl\":\"https:\/\/www.fir3net.com\/wp-content\/uploads\/Fir3net-Background-Logo-compressed.png\",\"width\":390,\"height\":88,\"caption\":\"Fir3net\"},\"image\":{\"@id\":\"https:\/\/www.fir3net.com\/#\/schema\/logo\/image\/\"}},{\"@type\":\"Person\",\"@id\":\"https:\/\/www.fir3net.com\/#\/schema\/person\/ab35009601b7687ee1c5310be6038037\",\"name\":\"Rick Donato\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/www.fir3net.com\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/secure.gravatar.com\/avatar\/d75d69a54c0ca3b32c24c3a9703b623c?s=96&d=mm&r=g\",\"contentUrl\":\"https:\/\/secure.gravatar.com\/avatar\/d75d69a54c0ca3b32c24c3a9703b623c?s=96&d=mm&r=g\",\"caption\":\"Rick Donato\"},\"description\":\"Rick Donato is a Network Automation Architect\/Evangelist and the founder of Packet Coders.\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"TCP Flags Definition and Operation - Fir3net","description":"&nbsp; URG This flag indicates that the packet contains urgent data that should be processed as soon as possible. This flag is used to provide two virtual","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/www.fir3net.com\/uncategorized\/tcp-flags.html","og_locale":"en_US","og_type":"article","og_title":"TCP Flags Definition and Operation - Fir3net","og_description":"&nbsp; URG This flag indicates that the packet contains urgent data that should be processed as soon as possible. This flag is used to provide two virtual","og_url":"https:\/\/www.fir3net.com\/uncategorized\/tcp-flags.html","og_site_name":"Fir3net","article_published_time":"1999-01-01T00:00:00+00:00","article_modified_time":"2021-07-27T17:55:18+00:00","author":"Rick Donato","twitter_card":"summary_large_image","twitter_misc":{"Written by":"Rick Donato","Est. reading time":"1 minute"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/www.fir3net.com\/uncategorized\/tcp-flags.html#article","isPartOf":{"@id":"https:\/\/www.fir3net.com\/uncategorized\/tcp-flags.html"},"author":{"name":"Rick Donato","@id":"https:\/\/www.fir3net.com\/#\/schema\/person\/ab35009601b7687ee1c5310be6038037"},"headline":"TCP Flags Definition and Operation","datePublished":"1999-01-01T00:00:00+00:00","dateModified":"2021-07-27T17:55:18+00:00","mainEntityOfPage":{"@id":"https:\/\/www.fir3net.com\/uncategorized\/tcp-flags.html"},"wordCount":302,"publisher":{"@id":"https:\/\/www.fir3net.com\/#organization"},"articleSection":["Networking Concepts"],"inLanguage":"en-US"},{"@type":"WebPage","@id":"https:\/\/www.fir3net.com\/uncategorized\/tcp-flags.html","url":"https:\/\/www.fir3net.com\/uncategorized\/tcp-flags.html","name":"TCP Flags Definition and Operation - Fir3net","isPartOf":{"@id":"https:\/\/www.fir3net.com\/#website"},"datePublished":"1999-01-01T00:00:00+00:00","dateModified":"2021-07-27T17:55:18+00:00","description":"&nbsp; URG This flag indicates that the packet contains urgent data that should be processed as soon as possible. This flag is used to provide two virtual","breadcrumb":{"@id":"https:\/\/www.fir3net.com\/uncategorized\/tcp-flags.html#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.fir3net.com\/uncategorized\/tcp-flags.html"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/www.fir3net.com\/uncategorized\/tcp-flags.html#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/www.fir3net.com\/"},{"@type":"ListItem","position":2,"name":"Networking","item":"https:\/\/www.fir3net.com\/networking"},{"@type":"ListItem","position":3,"name":"Networking Concepts","item":"https:\/\/www.fir3net.com\/networking\/concepts-networking"},{"@type":"ListItem","position":4,"name":"TCP Flags Definition and Operation"}]},{"@type":"WebSite","@id":"https:\/\/www.fir3net.com\/#website","url":"https:\/\/www.fir3net.com\/","name":"Fir3net","description":"Keeping you in the know","publisher":{"@id":"https:\/\/www.fir3net.com\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.fir3net.com\/?s={search_term_string}"},"query-input":"required name=search_term_string"}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/www.fir3net.com\/#organization","name":"Fir3net","url":"https:\/\/www.fir3net.com\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.fir3net.com\/#\/schema\/logo\/image\/","url":"https:\/\/www.fir3net.com\/wp-content\/uploads\/Fir3net-Background-Logo-compressed.png","contentUrl":"https:\/\/www.fir3net.com\/wp-content\/uploads\/Fir3net-Background-Logo-compressed.png","width":390,"height":88,"caption":"Fir3net"},"image":{"@id":"https:\/\/www.fir3net.com\/#\/schema\/logo\/image\/"}},{"@type":"Person","@id":"https:\/\/www.fir3net.com\/#\/schema\/person\/ab35009601b7687ee1c5310be6038037","name":"Rick Donato","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.fir3net.com\/#\/schema\/person\/image\/","url":"https:\/\/secure.gravatar.com\/avatar\/d75d69a54c0ca3b32c24c3a9703b623c?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/d75d69a54c0ca3b32c24c3a9703b623c?s=96&d=mm&r=g","caption":"Rick Donato"},"description":"Rick Donato is a Network Automation Architect\/Evangelist and the founder of Packet Coders."}]}},"_links":{"self":[{"href":"https:\/\/www.fir3net.com\/wp-json\/wp\/v2\/posts\/278"}],"collection":[{"href":"https:\/\/www.fir3net.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.fir3net.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.fir3net.com\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.fir3net.com\/wp-json\/wp\/v2\/comments?post=278"}],"version-history":[{"count":0,"href":"https:\/\/www.fir3net.com\/wp-json\/wp\/v2\/posts\/278\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.fir3net.com\/wp-json\/wp\/v2\/media?parent=278"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.fir3net.com\/wp-json\/wp\/v2\/categories?post=278"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.fir3net.com\/wp-json\/wp\/v2\/tags?post=278"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}