{"id":4998,"date":"2019-11-25T17:54:29","date_gmt":"2019-11-25T09:54:29","guid":{"rendered":"https:\/\/www.alfredivy.per.sg\/blogger\/?p=4998"},"modified":"2025-07-14T19:17:48","modified_gmt":"2025-07-14T11:17:48","slug":"cdp-is-a-lifesaver","status":"publish","type":"post","link":"https:\/\/www.alfredivy.sg\/blogger\/2019\/11\/cdp-is-a-lifesaver\/","title":{"rendered":"CDP is a lifesaver"},"content":{"rendered":"\n<p>Cisco Discovery Protocol or CDP as I have discovered is a lifesaver.<\/p>\n\n\n\n<!--more-->\n\n\n\n<p>I wanted to connect my switch to another.  The customer has no idea what is the hostname.  So I just cascaded my switch off an empty port and typed the following:<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>show CDP neighbour<\/p>\n<\/blockquote>\n\n\n\n<pre class=\"wp-block-preformatted\">SW2#cdp<br>Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge<br>                  S - Switch, H - Host, I - IGMP, r - Repeater, P - Phone, <br>                  D - Remote, C - CVTA, M - Two-port Mac Relay <\/pre>\n\n\n\n<pre class=\"wp-block-preformatted\">Device ID        Local Intrfce     Holdtme    Capability  Platform  Port ID<br>ac17c111e999     Gig 1\/0\/1         178          R S   Meraki MR Port 0<br>ac17c111e998     Gig 1\/0\/3         152          R S   Meraki MR Port 0<br>SW1              Gig 1\/0\/48        179          S I   WS-C3650- Gig 1\/0\/48<br>SW3              Gig 1\/0\/47        165          S I   WS-C3650- Gig 1\/0\/47<br>ac17c111e997     Gig 1\/0\/4         169          R S   Meraki MR Port 0<br>ac17c111e996     Gig 1\/0\/2         135          R S   Meraki MR Port 0<\/pre>\n\n\n\n<pre class=\"wp-block-preformatted\">Total cdp entries displayed : 6\nSW2#<\/pre>\n\n\n\n<p>CDP showed the hostname of the switch I was connected to.  No messing around with VLAN required.  The command <\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>show CDP entry &lt;hostname><\/p>\n<\/blockquote>\n\n\n\n<pre class=\"wp-block-preformatted\">SW2#sh cdp entry SW1\n--------------------\nDevice ID: SW2\nEntry address(es): \n  IP address: 1.1.1.1\nPlatform: cisco WS-C3650-48PS,  Capabilities: Switch IGMP \nInterface: GigabitEthernet1\/0\/48,  Port ID (outgoing port): GigabitEthernet1\/0\/48\nHoldtime : 153 sec<\/pre>\n\n\n\n<pre>Version :<br \/>Cisco IOS Software [Fuji], Catalyst L3 Switch Software (CAT3K_CAA-UNIVERSALK9-M), Version 16.9.4, RELEASE SOFTWARE (fc2)<br \/>Technical Support: http:\/\/www.cisco.com\/techsupport<br \/>Copyright (c) 1986-2019 by Cisco Systems, Inc.<br \/>Compiled Thu 22-Aug-19 17:33 by mcpre<\/pre>\n\n\n\n<pre class=\"wp-block-preformatted\">advertisement version: 2\nVTP Management Domain: ''\nNative VLAN: 1\nDuplex: full\nManagement address(es): \n  IP address: 2.2.2.2<\/pre>\n\n\n\n<p>It displays the management IP and additional information.  This really saves me the hassle of scheduling a password recovery.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Cisco Discovery Protocol or CDP as I have discovered is a lifesaver.<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[246],"tags":[440],"class_list":["post-4998","post","type-post","status-publish","format-standard","hentry","category-networks","tag-cisco"],"_links":{"self":[{"href":"https:\/\/www.alfredivy.sg\/blogger\/wp-json\/wp\/v2\/posts\/4998","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.alfredivy.sg\/blogger\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.alfredivy.sg\/blogger\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.alfredivy.sg\/blogger\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.alfredivy.sg\/blogger\/wp-json\/wp\/v2\/comments?post=4998"}],"version-history":[{"count":3,"href":"https:\/\/www.alfredivy.sg\/blogger\/wp-json\/wp\/v2\/posts\/4998\/revisions"}],"predecessor-version":[{"id":6467,"href":"https:\/\/www.alfredivy.sg\/blogger\/wp-json\/wp\/v2\/posts\/4998\/revisions\/6467"}],"wp:attachment":[{"href":"https:\/\/www.alfredivy.sg\/blogger\/wp-json\/wp\/v2\/media?parent=4998"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.alfredivy.sg\/blogger\/wp-json\/wp\/v2\/categories?post=4998"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.alfredivy.sg\/blogger\/wp-json\/wp\/v2\/tags?post=4998"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}