{"id":250,"date":"2009-03-04T01:06:15","date_gmt":"2009-03-04T07:06:15","guid":{"rendered":"http:\/\/gregsowell.com\/?p=250"},"modified":"2009-02-22T19:59:51","modified_gmt":"2009-02-23T01:59:51","slug":"hidden-internal-vlans-on-a-cisco-6500","status":"publish","type":"post","link":"https:\/\/gregsowell.com\/?p=250","title":{"rendered":"Hidden Internal VLANs on a Cisco 6500"},"content":{"rendered":"<p>Something interesting about a Cisco 6500 is that it uses hidden internal VLANs.  Most people will never be aware of this because the assignment starts in the extended VLAN range.  An internal VLAN is created for every port in your chassis that is not an access port.<\/p>\n<p>The command to view these VLANs is &#8220;<a title=\"show vlan internal usage\" href=\"http:\/\/www.cisco.com\/en\/US\/docs\/switches\/lan\/catalyst6500\/ios\/12.1E\/native\/command\/reference\/show4.html#wp2015605\" target=\"_blank\">show vlan internal usage<\/a>&#8220;.<\/p>\n<blockquote><p>6509-router#show vlan internal usage<\/p>\n<p>VLAN Usage<br \/>\n&#8212;- &#8212;&#8212;&#8212;&#8212;&#8212;&#8212;&#8211;<br \/>\n1006 online diag vlan0<br \/>\n1007 online diag vlan1<br \/>\n1008 online diag vlan2<br \/>\n1009 online diag vlan3<br \/>\n1010 online diag vlan4<br \/>\n1011 online diag vlan5<br \/>\n1012 PM vlan process (trunk tagging)<br \/>\n1013 Control Plane Protection<br \/>\n1014 L3 multicast partial shortcuts for VPN 0<br \/>\n1015 Egress internal vlan<br \/>\n1016 Multicast VPN 0 QOS vlan<br \/>\n1017 IPv6 Multicast Egress multicast<br \/>\n1018 GigabitEthernet5\/1<br \/>\n1019 vrf_0_vlan0<br \/>\n1020 GigabitEthernet6\/2<br \/>\n1021 FastEthernet9\/7<br \/>\n1022 FastEthernet9\/6<br \/>\n1023 FastEthernet9\/28<br \/>\n1024 FastEthernet9\/25<br \/>\n1025 FastEthernet9\/13<\/p><\/blockquote>\n<p>So, when beginning to do VLAN allocation planning, be sure to take this into account.  It is best to begin your extended range VLANs at 1300 or above.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Something interesting about a Cisco 6500 is that it uses hidden internal VLANs. Most people will never be aware of this because the assignment\u2026<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[16,8],"tags":[],"class_list":["post-250","post","type-post","status-publish","format-standard","hentry","category-cisco","category-networking"],"_links":{"self":[{"href":"https:\/\/gregsowell.com\/index.php?rest_route=\/wp\/v2\/posts\/250","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/gregsowell.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/gregsowell.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/gregsowell.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/gregsowell.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=250"}],"version-history":[{"count":5,"href":"https:\/\/gregsowell.com\/index.php?rest_route=\/wp\/v2\/posts\/250\/revisions"}],"predecessor-version":[{"id":255,"href":"https:\/\/gregsowell.com\/index.php?rest_route=\/wp\/v2\/posts\/250\/revisions\/255"}],"wp:attachment":[{"href":"https:\/\/gregsowell.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=250"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gregsowell.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=250"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gregsowell.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=250"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}