{"id":1012989,"date":"2023-09-03T23:44:31","date_gmt":"2023-09-03T23:44:31","guid":{"rendered":"https:\/\/beta-new.inhand.com\/?p=6779"},"modified":"2026-06-04T00:44:27","modified_gmt":"2026-06-04T00:44:27","slug":"what-is-ospf","status":"publish","type":"post","link":"https:\/\/www.inhand.com\/en\/support\/blogs\/what-is-ospf","title":{"rendered":"What is Open Shortest Path First (OSPF)?"},"content":{"rendered":"\t\t<div data-elementor-type=\"wp-post\" data-elementor-id=\"1012989\" class=\"elementor elementor-1012989\" data-elementor-post-type=\"post\">\n\t\t\t\t<div class=\"elementor-element elementor-element-f5deb9f e-con-full anli_box e-flex e-con e-parent\" data-id=\"f5deb9f\" data-element_type=\"container\">\n\t\t<div class=\"elementor-element elementor-element-6c1a9e e-con-full anli_box_l e-flex e-con e-child\" data-id=\"6c1a9e\" data-element_type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-34437fe7 elementor-widget-mobile__width-inherit elementor-widget elementor-widget-heading\" data-id=\"34437fe7\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">What is Open Shortest Path First (OSPF)?<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-3775149e e-con-full e-flex e-con e-child\" data-id=\"3775149e\" data-element_type=\"container\">\n\t\t\t\t<div class=\"elementor-element elementor-element-10a10b91 elementor-widget elementor-widget-heading\" data-id=\"10a10b91\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Blogs<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-6bac9b35 e-con-full e-flex e-con e-child\" data-id=\"6bac9b35\" data-element_type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-788fe74d elementor-widget-mobile__width-inherit elementor-widget elementor-widget-heading\" data-id=\"788fe74d\" data-element_type=\"widget\" id=\"maodian1\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Key Takeaways<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-257fbef5 elementor-widget elementor-widget-heading\" data-id=\"257fbef5\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">OSPF is a typical Link-state routing protocol, which is generally used in the same routing domain.<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-6167c32 elementor-widget elementor-widget-text-editor\" data-id=\"6167c32\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p><strong>What is OSPF?<\/strong><\/p><p>OSPF is a typical Link-state routing protocol, which is generally used in the same routing domain. Here, the routing domain refers to an Autonomous System (AS), which refers to a group of networks that exchange routing information with each other through a unified routing policy or protocol. In this AS, all OSPF routers maintain the same database describing the structure of this AS, which stores the state information of the corresponding links in the routing domain. It is through this database that OSPF routers calculate their OSPF routing tables.<\/p><p>As a link-state routing protocol, OSPF transmits the link-state multicast data LSA(Link State Advertisement) to all routers in a certain area, which is different from the distance vector routing protocol. Routers running distance vector routing protocol pass some or all routing tables to their neighbors.<\/p><p>On the security of information exchange, OSPF stipulates that any information exchange between routers can be Authentication when necessary, so as to ensure that only trusted routers can spread routing information. OSPF supports a variety of authentication mechanisms, and allows different authentication mechanisms to be adopted among different areas. The application of OSPF link state algorithm in broadcast network (such as Ethernet) is optimized to make the best use of hardware broadcast capability to deliver link state messages. Usually, a node in the topology diagram of link state algorithm represents a router. If all k routers are connected to Ethernet, when the link state is broadcast, the number of messages about these k routers will reach k square. Therefore, OSPF allows a node to represent a broadcast network in the topology diagram. All routers in each broadcast network send link status messages to report the link status of the routers in the network.<\/p><p><span style=\"font-size: inherit; text-align: inherit; font-family: var( --e-global-typography-text-font-family ), Sans-serif; font-weight: var( --e-global-typography-text-font-weight ); background-color: var(--palettecolor8); color: var(--color); font-style: var(--fontStyle, inherit); letter-spacing: var(--letterSpacing); text-transform: var(--textTransform);\">\u00a0<\/span><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-aca051a elementor-widget elementor-widget-text-editor\" data-id=\"aca051a\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p><strong>Principle of operation<\/strong><\/p><p>To put it simply, OSPF means that two adjacent routers become neighbors by sending messages, and then neighbors send link state information to each other to form an adjacent relationship. After that, each router calculates a route according to the shortest path algorithm and puts it in the OSPF routing table. Compared with other routes, OSPF routes are better added to the global routing table. The whole process uses five kinds of messages, three stages and four tables.<\/p><p><strong>Five kinds of messages<\/strong><\/p><p>Hello message: Establish and maintain neighbor relationship.<\/p><p>DBD message: sends link state header information.<\/p><p>LSR message: Send the required link state header information found out from DBD to neighbors, and request complete information.<\/p><p>LSU message: send complete information corresponding to the header information of LSR request to neighbors.<\/p><p>LSACK: Confirm the LSU message after receiving it.<\/p><p><strong>Three stages<\/strong><\/p><p>Neighbor discovery: Neighbor relationship is formed by sending Hello message.<\/p><p>Route announcement: Neighbors send link state information to form an adjacency relationship.<\/p><p>Calculation: Calculate the routing table according to the shortest path algorithm.<\/p><p><strong>Four tables<br \/><\/strong><\/p><p>Neighbor table: mainly records the routers that form the neighbor relationship.<\/p><p>Link state database: records link state information.<\/p><p>Routing table: obtained from the link state database.<\/p><p>Global routing table: OSPF routing is compared with others.<\/p><p>\u00a0<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-1e87d53 e-con-full e-flex e-con e-child\" data-id=\"1e87d53\" data-element_type=\"container\">\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-a14c13b e-con-full anli_l_st e-flex e-con e-child\" data-id=\"a14c13b\" data-element_type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;,&quot;sticky&quot;:&quot;top&quot;,&quot;sticky_offset&quot;:90,&quot;sticky_effects_offset&quot;:100,&quot;sticky_anchor_link_offset&quot;:100,&quot;sticky_parent&quot;:&quot;yes&quot;,&quot;sticky_on&quot;:[&quot;desktop&quot;,&quot;tablet&quot;,&quot;mobile&quot;]}\">\n\t\t<div class=\"elementor-element elementor-element-1da7e082 e-con-full e-flex e-con e-child\" data-id=\"1da7e082\" data-element_type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-69473ed elementor-widget elementor-widget-heading\" data-id=\"69473ed\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Read More <\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-108ac635 elementor-widget elementor-widget-shortcode\" data-id=\"108ac635\" data-element_type=\"widget\" data-widget_type=\"shortcode.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<div class=\"elementor-shortcode\">    <style>\n        \/* --- \u8fd9\u91cc\u7684\u53c2\u6570\u5168\u90e8\u4fdd\u7559\u4f60\u7684\u4fee\u6539 --- *\/\n        .vpro-wrapper {\n            width: 100%;\n            max-width: 25rem;\n            height: 38.5rem;\n            overflow-y: auto;\n            overflow-x: hidden;\n            \/* 1. \u589e\u52a0\u5e95\u90e8\u5185\u8fb9\u8ddd\uff0c\u5236\u9020\u865a\u7a7a\u611f *\/\n            padding: 0.3125rem 0.3125rem 0rem 0.3125rem;\n            scrollbar-width: thin;\n            box-sizing: border-box;\n        }\n\n        .vpro-wrapper::-webkit-scrollbar { width: 0.25rem; }\n        .vpro-wrapper::-webkit-scrollbar-thumb { background: #ccc; border-radius: 0.625rem; }\n\n        .vpro-item {\n            width: 100%;\n            height: 21rem;\n            margin-bottom: 1rem;\n            background: #fff;\n            border: 0.0625rem solid #D7D7D7;\n            border-radius: 0.5rem;\n            display: flex;\n            flex-direction: column;\n            flex-shrink: 0;\n            overflow: hidden;\n            box-sizing: border-box;\n            transition: all 0.3s ease;\n        }\n\n        .vpro-item:hover {\n            box-shadow: 0 0.5rem 1.25rem rgba(0,0,0,0.08);\n            transform: translateY(-0.125rem);\n        }\n\n        .vpro-img-box {\n            width: 100%;\n            height: 14rem; \/* \u4fdd\u7559\u4f60\u6539\u7684 10rem *\/\n            overflow: hidden;\n            background: #f5f5f5;\n            flex-shrink: 0;\n        }\n\n        .vpro-img-box img {\n            width: 100%;\n            height: 100%;\n            object-fit: cover;\n            object-position: center;\n            display: block;\n        }\n\n        .vpro-content {\n            padding: 0.5rem 0.5rem 0.8rem 1.25rem;\n            flex-grow: 1;\n            display: flex;\n            align-items: center;\n        }\n\n        .vpro-title {\n            font-size: 1.25rem; \/* \u4fdd\u7559\u4f60\u6539\u7684 1.5rem *\/\n            font-weight: 500;\n            line-height: 1.4;\n            color: #000;\n            display: -webkit-box;\n            -webkit-line-clamp: 3; \/* \u4fdd\u7559\u4f60\u6539\u7684 3 \u884c *\/\n            -webkit-box-orient: vertical;\n            overflow: hidden;\n            text-decoration: none;\n        }\n\n        .vpro-title a {\n            text-decoration: none;\n            color: inherit;\n        }\n\n        \/* 2. \u589e\u52a0\u4e00\u4e2a\u7269\u7406\u5360\u4f4d\u7b26\uff0c\u786e\u4fdd\u6eda\u52a8\u5230\u5e95\u90e8\u6709\u4f59\u91cf *\/\n        .vpro-bottom-spacer {\n            height: 4rem;\n            width: 100%;\n            flex-shrink: 0;\n        }\n    <\/style>\n\n    <div class=\"vpro-wrapper\">\n                    <div class=\"vpro-item\">\n                <div class=\"vpro-img-box\">\n                    <a href=\"https:\/\/www.inhand.com\/en\/support\/blogs\/failover-features-on-a-router\">\n                                                    <img fetchpriority=\"high\" decoding=\"async\" width=\"600\" height=\"352\" src=\"https:\/\/www.inhand.com\/wp-content\/uploads\/2026\/03\/failover.png\" class=\"attachment-full size-full wp-post-image\" alt=\"Diagram demonstrating router failover features for reliable connectivity in industrial IoT networks.\" srcset=\"https:\/\/www.inhand.com\/wp-content\/uploads\/2026\/03\/failover.png 600w, https:\/\/www.inhand.com\/wp-content\/uploads\/2026\/03\/failover-300x176.png 300w, https:\/\/www.inhand.com\/wp-content\/uploads\/2026\/03\/failover-18x12.png 18w\" sizes=\"(max-width: 600px) 100vw, 600px\" \/>                                            <\/a>\n                <\/div>\n                <div class=\"vpro-content\">\n                    <div class=\"vpro-title\">\n                        <a href=\"https:\/\/www.inhand.com\/en\/support\/blogs\/failover-features-on-a-router\">What Are the Failover Features on a Router?<\/a>\n                    <\/div>\n                <\/div>\n            <\/div>\n                    <div class=\"vpro-item\">\n                <div class=\"vpro-img-box\">\n                    <a href=\"https:\/\/www.inhand.com\/en\/support\/blogs\/why-do-we-need-routing-protocols\">\n                                                    <img decoding=\"async\" width=\"600\" height=\"352\" src=\"https:\/\/www.inhand.com\/wp-content\/uploads\/2026\/03\/routing-protocols-1.png\" class=\"attachment-full size-full wp-post-image\" alt=\"routing-protocols\" srcset=\"https:\/\/www.inhand.com\/wp-content\/uploads\/2026\/03\/routing-protocols-1.png 600w, https:\/\/www.inhand.com\/wp-content\/uploads\/2026\/03\/routing-protocols-1-300x176.png 300w, https:\/\/www.inhand.com\/wp-content\/uploads\/2026\/03\/routing-protocols-1-18x12.png 18w\" sizes=\"(max-width: 600px) 100vw, 600px\" \/>                                            <\/a>\n                <\/div>\n                <div class=\"vpro-content\">\n                    <div class=\"vpro-title\">\n                        <a href=\"https:\/\/www.inhand.com\/en\/support\/blogs\/why-do-we-need-routing-protocols\">Why Do We Need the Routing Protocol?<\/a>\n                    <\/div>\n                <\/div>\n            <\/div>\n                    <div class=\"vpro-item\">\n                <div class=\"vpro-img-box\">\n                    <a href=\"https:\/\/www.inhand.com\/en\/support\/blogs\/cloud-edge-coordination-in-iiot\">\n                                                    <img decoding=\"async\" width=\"600\" height=\"352\" src=\"https:\/\/www.inhand.com\/wp-content\/uploads\/2026\/03\/cloudedge-coordinated-thrive-in-the-iiot-era.png\" class=\"attachment-full size-full wp-post-image\" alt=\"cloud+edge-coordinated-thrive-in-the-iiot-era\" srcset=\"https:\/\/www.inhand.com\/wp-content\/uploads\/2026\/03\/cloudedge-coordinated-thrive-in-the-iiot-era.png 600w, https:\/\/www.inhand.com\/wp-content\/uploads\/2026\/03\/cloudedge-coordinated-thrive-in-the-iiot-era-300x176.png 300w, https:\/\/www.inhand.com\/wp-content\/uploads\/2026\/03\/cloudedge-coordinated-thrive-in-the-iiot-era-18x12.png 18w\" sizes=\"(max-width: 600px) 100vw, 600px\" \/>                                            <\/a>\n                <\/div>\n                <div class=\"vpro-content\">\n                    <div class=\"vpro-title\">\n                        <a href=\"https:\/\/www.inhand.com\/en\/support\/blogs\/cloud-edge-coordination-in-iiot\">\u201cCloud + Edge\u201d Coordinated, Thrive in the IIoT Era<\/a>\n                    <\/div>\n                <\/div>\n            <\/div>\n        \n        <div class=\"vpro-bottom-spacer\"><\/div>\n    <\/div>\n    <\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"<p>What is Open Shortest Path First (OSPF)? What is OSPF? OSPF is a typical Link-state routing protocol, which is generally used in the same routing domain. Here, the routing domain refers to an Autonomous System (AS), which refers to a group&#8230; Principle of operation To put it simply, OSPF means that two adjacent routers become [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":960028,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"elementor_header_footer","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[817],"tags":[],"case_tag":[],"class_list":["post-1012989","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blogs"],"blocksy_meta":[],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v26.6 (Yoast SEO v26.6) - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>Understanding OSPF: Link-State Routing Protocol Fundamentals<\/title>\n<meta name=\"description\" content=\"Learn how OSPF works as a link-state routing protocol with authentication security. Explore OSPF&#039;s five message types, three operational stages, and four key tables for efficient routing.\" \/>\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.inhand.com\/en\/support\/blogs\/what-is-ospf\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"What is Open Shortest Path First (OSPF)?\" \/>\n<meta property=\"og:description\" content=\"OSPF is a typical Link-state routing protocol, which is generally used in the same routing domain.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.inhand.com\/en\/support\/blogs\/what-is-ospf\" \/>\n<meta property=\"og:site_name\" content=\"InHand Networks\" \/>\n<meta property=\"article:published_time\" content=\"2023-09-03T23:44:31+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2026-06-04T00:44:27+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/www.inhand.com\/wp-content\/uploads\/2026\/03\/OSPF-1.png\" \/>\n\t<meta property=\"og:image:width\" content=\"900\" \/>\n\t<meta property=\"og:image:height\" content=\"596\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/png\" \/>\n<meta name=\"author\" content=\"admin\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:title\" content=\"What is Open Shortest Path First (OSPF)?\" \/>\n<meta name=\"twitter:description\" content=\"OSPF is a typical Link-state routing protocol, which is generally used in the same routing domain.\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"admin\" \/>\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.inhand.com\/en\/support\/blogs\/what-is-ospf#article\",\"isPartOf\":{\"@id\":\"https:\/\/www.inhand.com\/en\/support\/blogs\/what-is-ospf\"},\"author\":{\"name\":\"admin\",\"@id\":\"https:\/\/www.inhand.com\/en\/#\/schema\/person\/f28b5f5eb652f2ac06a75a465b789734\"},\"headline\":\"What is Open Shortest Path First (OSPF)?\",\"datePublished\":\"2023-09-03T23:44:31+00:00\",\"dateModified\":\"2026-06-04T00:44:27+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\/\/www.inhand.com\/en\/support\/blogs\/what-is-ospf\"},\"wordCount\":81,\"publisher\":{\"@id\":\"https:\/\/www.inhand.com\/en\/#organization\"},\"image\":{\"@id\":\"https:\/\/www.inhand.com\/en\/support\/blogs\/what-is-ospf#primaryimage\"},\"thumbnailUrl\":\"https:\/\/www.inhand.com\/wp-content\/uploads\/2026\/03\/OSPF-1.png\",\"articleSection\":[\"blog\"],\"inLanguage\":\"en-US\"},{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.inhand.com\/en\/support\/blogs\/what-is-ospf\",\"url\":\"https:\/\/www.inhand.com\/en\/support\/blogs\/what-is-ospf\",\"name\":\"Understanding OSPF: Link-State Routing Protocol Fundamentals\",\"isPartOf\":{\"@id\":\"https:\/\/www.inhand.com\/en\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\/\/www.inhand.com\/en\/support\/blogs\/what-is-ospf#primaryimage\"},\"image\":{\"@id\":\"https:\/\/www.inhand.com\/en\/support\/blogs\/what-is-ospf#primaryimage\"},\"thumbnailUrl\":\"https:\/\/www.inhand.com\/wp-content\/uploads\/2026\/03\/OSPF-1.png\",\"datePublished\":\"2023-09-03T23:44:31+00:00\",\"dateModified\":\"2026-06-04T00:44:27+00:00\",\"description\":\"Learn how OSPF works as a link-state routing protocol with authentication security. Explore OSPF's five message types, three operational stages, and four key tables for efficient routing.\",\"breadcrumb\":{\"@id\":\"https:\/\/www.inhand.com\/en\/support\/blogs\/what-is-ospf#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/www.inhand.com\/en\/support\/blogs\/what-is-ospf\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/www.inhand.com\/en\/support\/blogs\/what-is-ospf#primaryimage\",\"url\":\"https:\/\/www.inhand.com\/wp-content\/uploads\/2026\/03\/OSPF-1.png\",\"contentUrl\":\"https:\/\/www.inhand.com\/wp-content\/uploads\/2026\/03\/OSPF-1.png\",\"width\":900,\"height\":596,\"caption\":\"See how OSPF facilitates efficient communication in industrial IoT infrastructure.\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/www.inhand.com\/en\/support\/blogs\/what-is-ospf#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"\u9996\u9875\",\"item\":\"https:\/\/www.inhand.com\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"What is Open Shortest Path First (OSPF)?\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/www.inhand.com\/en\/#website\",\"url\":\"https:\/\/www.inhand.com\/en\/\",\"name\":\"inhand\",\"description\":\"\",\"publisher\":{\"@id\":\"https:\/\/www.inhand.com\/en\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/www.inhand.com\/en\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\/\/www.inhand.com\/en\/#organization\",\"name\":\"inhand\",\"url\":\"https:\/\/www.inhand.com\/en\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/www.inhand.com\/en\/#\/schema\/logo\/image\/\",\"url\":\"https:\/\/www.inhand.com\/wp-content\/uploads\/2025\/10\/LOGO.png\",\"contentUrl\":\"https:\/\/www.inhand.com\/wp-content\/uploads\/2025\/10\/LOGO.png\",\"width\":684,\"height\":120,\"caption\":\"inhand\"},\"image\":{\"@id\":\"https:\/\/www.inhand.com\/en\/#\/schema\/logo\/image\/\"}},{\"@type\":\"Person\",\"@id\":\"https:\/\/www.inhand.com\/en\/#\/schema\/person\/f28b5f5eb652f2ac06a75a465b789734\",\"name\":\"admin\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/www.inhand.com\/en\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/secure.gravatar.com\/avatar\/629c75063bd057cce2f443041efb70c2b7c38a823722dc38d646dcbac08e4183?s=96&d=mm&r=g\",\"contentUrl\":\"https:\/\/secure.gravatar.com\/avatar\/629c75063bd057cce2f443041efb70c2b7c38a823722dc38d646dcbac08e4183?s=96&d=mm&r=g\",\"caption\":\"admin\"},\"sameAs\":[\"https:\/\/beta-new.inhand.com\"],\"url\":\"https:\/\/www.inhand.com\/en\/author\/admin\"}]}<\/script>\n<!-- \/ Yoast SEO Premium plugin. -->","yoast_head_json":{"title":"Understanding OSPF: Link-State Routing Protocol Fundamentals","description":"Learn how OSPF works as a link-state routing protocol with authentication security. Explore OSPF's five message types, three operational stages, and four key tables for efficient routing.","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.inhand.com\/en\/support\/blogs\/what-is-ospf","og_locale":"en_US","og_type":"article","og_title":"What is Open Shortest Path First (OSPF)?","og_description":"OSPF is a typical Link-state routing protocol, which is generally used in the same routing domain.","og_url":"https:\/\/www.inhand.com\/en\/support\/blogs\/what-is-ospf","og_site_name":"InHand Networks","article_published_time":"2023-09-03T23:44:31+00:00","article_modified_time":"2026-06-04T00:44:27+00:00","og_image":[{"width":900,"height":596,"url":"https:\/\/www.inhand.com\/wp-content\/uploads\/2026\/03\/OSPF-1.png","type":"image\/png"}],"author":"admin","twitter_card":"summary_large_image","twitter_title":"What is Open Shortest Path First (OSPF)?","twitter_description":"OSPF is a typical Link-state routing protocol, which is generally used in the same routing domain.","twitter_misc":{"Written by":"admin","Est. reading time":"1 minute"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/www.inhand.com\/en\/support\/blogs\/what-is-ospf#article","isPartOf":{"@id":"https:\/\/www.inhand.com\/en\/support\/blogs\/what-is-ospf"},"author":{"name":"admin","@id":"https:\/\/www.inhand.com\/en\/#\/schema\/person\/f28b5f5eb652f2ac06a75a465b789734"},"headline":"What is Open Shortest Path First (OSPF)?","datePublished":"2023-09-03T23:44:31+00:00","dateModified":"2026-06-04T00:44:27+00:00","mainEntityOfPage":{"@id":"https:\/\/www.inhand.com\/en\/support\/blogs\/what-is-ospf"},"wordCount":81,"publisher":{"@id":"https:\/\/www.inhand.com\/en\/#organization"},"image":{"@id":"https:\/\/www.inhand.com\/en\/support\/blogs\/what-is-ospf#primaryimage"},"thumbnailUrl":"https:\/\/www.inhand.com\/wp-content\/uploads\/2026\/03\/OSPF-1.png","articleSection":["blog"],"inLanguage":"en-US"},{"@type":"WebPage","@id":"https:\/\/www.inhand.com\/en\/support\/blogs\/what-is-ospf","url":"https:\/\/www.inhand.com\/en\/support\/blogs\/what-is-ospf","name":"Understanding OSPF: Link-State Routing Protocol Fundamentals","isPartOf":{"@id":"https:\/\/www.inhand.com\/en\/#website"},"primaryImageOfPage":{"@id":"https:\/\/www.inhand.com\/en\/support\/blogs\/what-is-ospf#primaryimage"},"image":{"@id":"https:\/\/www.inhand.com\/en\/support\/blogs\/what-is-ospf#primaryimage"},"thumbnailUrl":"https:\/\/www.inhand.com\/wp-content\/uploads\/2026\/03\/OSPF-1.png","datePublished":"2023-09-03T23:44:31+00:00","dateModified":"2026-06-04T00:44:27+00:00","description":"Learn how OSPF works as a link-state routing protocol with authentication security. Explore OSPF's five message types, three operational stages, and four key tables for efficient routing.","breadcrumb":{"@id":"https:\/\/www.inhand.com\/en\/support\/blogs\/what-is-ospf#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.inhand.com\/en\/support\/blogs\/what-is-ospf"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.inhand.com\/en\/support\/blogs\/what-is-ospf#primaryimage","url":"https:\/\/www.inhand.com\/wp-content\/uploads\/2026\/03\/OSPF-1.png","contentUrl":"https:\/\/www.inhand.com\/wp-content\/uploads\/2026\/03\/OSPF-1.png","width":900,"height":596,"caption":"See how OSPF facilitates efficient communication in industrial IoT infrastructure."},{"@type":"BreadcrumbList","@id":"https:\/\/www.inhand.com\/en\/support\/blogs\/what-is-ospf#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"\u9996\u9875","item":"https:\/\/www.inhand.com\/"},{"@type":"ListItem","position":2,"name":"What is Open Shortest Path First (OSPF)?"}]},{"@type":"WebSite","@id":"https:\/\/www.inhand.com\/en\/#website","url":"https:\/\/www.inhand.com\/en\/","name":"inhand","description":"","publisher":{"@id":"https:\/\/www.inhand.com\/en\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.inhand.com\/en\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/www.inhand.com\/en\/#organization","name":"inhand","url":"https:\/\/www.inhand.com\/en\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.inhand.com\/en\/#\/schema\/logo\/image\/","url":"https:\/\/www.inhand.com\/wp-content\/uploads\/2025\/10\/LOGO.png","contentUrl":"https:\/\/www.inhand.com\/wp-content\/uploads\/2025\/10\/LOGO.png","width":684,"height":120,"caption":"inhand"},"image":{"@id":"https:\/\/www.inhand.com\/en\/#\/schema\/logo\/image\/"}},{"@type":"Person","@id":"https:\/\/www.inhand.com\/en\/#\/schema\/person\/f28b5f5eb652f2ac06a75a465b789734","name":"admin","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.inhand.com\/en\/#\/schema\/person\/image\/","url":"https:\/\/secure.gravatar.com\/avatar\/629c75063bd057cce2f443041efb70c2b7c38a823722dc38d646dcbac08e4183?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/629c75063bd057cce2f443041efb70c2b7c38a823722dc38d646dcbac08e4183?s=96&d=mm&r=g","caption":"admin"},"sameAs":["https:\/\/beta-new.inhand.com"],"url":"https:\/\/www.inhand.com\/en\/author\/admin"}]}},"_links":{"self":[{"href":"https:\/\/www.inhand.com\/en\/wp-json\/wp\/v2\/posts\/1012989","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.inhand.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.inhand.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.inhand.com\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.inhand.com\/en\/wp-json\/wp\/v2\/comments?post=1012989"}],"version-history":[{"count":1,"href":"https:\/\/www.inhand.com\/en\/wp-json\/wp\/v2\/posts\/1012989\/revisions"}],"predecessor-version":[{"id":1206718,"href":"https:\/\/www.inhand.com\/en\/wp-json\/wp\/v2\/posts\/1012989\/revisions\/1206718"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.inhand.com\/en\/wp-json\/wp\/v2\/media\/960028"}],"wp:attachment":[{"href":"https:\/\/www.inhand.com\/en\/wp-json\/wp\/v2\/media?parent=1012989"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.inhand.com\/en\/wp-json\/wp\/v2\/categories?post=1012989"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.inhand.com\/en\/wp-json\/wp\/v2\/tags?post=1012989"},{"taxonomy":"case_tag","embeddable":true,"href":"https:\/\/www.inhand.com\/en\/wp-json\/wp\/v2\/case_tag?post=1012989"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}