{"id":2976,"date":"2021-01-27T16:12:11","date_gmt":"2021-01-28T00:12:11","guid":{"rendered":"https:\/\/SUMMALAI.COM\/?p=2976"},"modified":"2021-01-27T16:12:13","modified_gmt":"2021-01-28T00:12:13","slug":"how-to-configure-allowed-vlans-on-cisco-trunk","status":"publish","type":"post","link":"https:\/\/SUMMALAI.COM\/?p=2976","title":{"rendered":"How to Configure Allowed VLANs on Cisco Trunk"},"content":{"rendered":"\n<p>By default, all VLANs are allowed across the trunk link. We can verify that using the&nbsp;<em>show interfaces trunk<\/em>&nbsp;command:<\/p>\n\n\n\n<figure class=\"wp-block-image\"><a href=\"https:\/\/geek-university.com\/wp-content\/uploads\/2015\/10\/show_interfaces_trunk.jpg\"><img decoding=\"async\" src=\"https:\/\/geek-university.com\/wp-content\/uploads\/2015\/10\/show_interfaces_trunk.jpg\" alt=\"show interfaces trunk\" class=\"wp-image-5162\"\/><\/a><\/figure>\n\n\n\n<p>You can prevent traffic from certain VLANs from traversing a trunked link using the following interface mode command:<\/p>\n\n\n\n<p><em>switchport trunk allowed vlan {add | all | except | remove} vlan-list<\/em><\/p>\n\n\n\n<p>For example, to prevent traffic from VLAN 5 to traverse the trunk link, you can use the following command:<\/p>\n\n\n\n<figure class=\"wp-block-image\"><a href=\"https:\/\/geek-university.com\/wp-content\/uploads\/2015\/10\/switchport_trunk_allowed_vlan_remove_command.jpg\"><img decoding=\"async\" src=\"https:\/\/geek-university.com\/wp-content\/uploads\/2015\/10\/switchport_trunk_allowed_vlan_remove_command.jpg\" alt=\"switchport trunk allowed vlan remove command\" class=\"wp-image-5168\"\/><\/a><\/figure>\n\n\n\n<p>To verify that the traffic from VLAN 5 will indeed be blocked from traversing a trunked link, use the&nbsp;<em>show interfaces trunk<\/em>&nbsp;command again:<\/p>\n\n\n\n<figure class=\"wp-block-image\"><a href=\"https:\/\/geek-university.com\/wp-content\/uploads\/2015\/10\/show_interfaces_trunk_command.jpg\"><img decoding=\"async\" src=\"https:\/\/geek-university.com\/wp-content\/uploads\/2015\/10\/show_interfaces_trunk_command.jpg\" alt=\"show interfaces trunk command\" class=\"wp-image-5163\"\/><\/a><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>By default, all VLANs are allowed across the trunk link. We can verify that using the&nbsp;show interfaces trunk&nbsp;command: You can prevent traffic from certain VLANs from traversing a trunked link using the following interface mode command: switchport trunk allowed vlan {add | all | except | remove} vlan-list For example, to prevent traffic from VLAN <a class=\"read-more\" href=\"https:\/\/SUMMALAI.COM\/?p=2976\">Read More<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_bbp_topic_count":0,"_bbp_reply_count":0,"_bbp_total_topic_count":0,"_bbp_total_reply_count":0,"_bbp_voice_count":0,"_bbp_anonymous_reply_count":0,"_bbp_topic_count_hidden":0,"_bbp_reply_count_hidden":0,"_bbp_forum_subforum_count":0,"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[9,19],"tags":[570],"class_list":["post-2976","post","type-post","status-publish","format-standard","hentry","category-networks","category-router-switch","tag-configure-allowed-vlan"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/SUMMALAI.COM\/index.php?rest_route=\/wp\/v2\/posts\/2976","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/SUMMALAI.COM\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/SUMMALAI.COM\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/SUMMALAI.COM\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/SUMMALAI.COM\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2976"}],"version-history":[{"count":1,"href":"https:\/\/SUMMALAI.COM\/index.php?rest_route=\/wp\/v2\/posts\/2976\/revisions"}],"predecessor-version":[{"id":2977,"href":"https:\/\/SUMMALAI.COM\/index.php?rest_route=\/wp\/v2\/posts\/2976\/revisions\/2977"}],"wp:attachment":[{"href":"https:\/\/SUMMALAI.COM\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2976"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/SUMMALAI.COM\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2976"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/SUMMALAI.COM\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2976"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}