{"id":969,"date":"2016-02-20T15:01:19","date_gmt":"2016-02-20T15:01:19","guid":{"rendered":"https:\/\/fir3netwp.gmsrrpobkbd.com\/2016\/02\/20\/udld\/"},"modified":"2023-01-06T15:41:06","modified_gmt":"2023-01-06T15:41:06","slug":"udld","status":"publish","type":"post","link":"https:\/\/www.fir3net.com\/Switches\/Cisco\/udld.html","title":{"rendered":"UDLD (Uni-Directional Link Detection)"},"content":{"rendered":"<p>Uni-Directional Link Detection detects links where either the transmit or receive path has failed. Used to monitor fibre-optic or twisted pair cabling for unidirectional links.<br \/>\nUDLD used periodic hello packets and uses the concept of echos to ensure neighbors are receiving UDLD the UDLD hellos.<\/p>\n<p>Supports 2 modes of operations,<\/p>\n<ul>\n<li>Normal &#8211; Port is placed into undetermined state. Port is not shutdown.<\/li>\n<li>Aggressive &#8211; Tries to get echo by sending hellow 8 times. Then places the interface into errdisable.<\/li>\n<\/ul>\n<h2>Globally<\/h2>\n<p>Disabled by default,<\/p>\n<pre>SW1(config) # udld enabled<\/pre>\n<h2>Per Interface<\/h2>\n<p>(fibre and copper)<\/p>\n<pre>SW1(config-if)# udld port aggressive<\/pre>\n<h2>UDLD Neighbors<\/h2>\n<pre>SW1# show udld neigh<\/pre>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Uni-Directional Link Detection detects links where either the transmit or receive path has failed. Used to monitor fibre-optic or twisted pair cabling for unidirectional links. UDLD used periodic hello packets and uses the concept of echos to ensure neighbors are receiving UDLD the UDLD hellos. Supports 2 modes of operations, Normal &#8211; Port is placed &#8230; <a title=\"UDLD (Uni-Directional Link Detection)\" class=\"read-more\" href=\"https:\/\/www.fir3net.com\/Switches\/Cisco\/udld.html\" aria-label=\"Read more about UDLD (Uni-Directional Link Detection)\">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":[22],"tags":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v22.5 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>UDLD (Uni-Directional Link Detection) - Fir3net<\/title>\n<meta name=\"description\" content=\"Uni-Directional Link Detection detects links where either the transmit or receive path has failed. 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