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--- cisco:certification_topics:ccie-ei:1.1.bi [2025/12/01 11:12] – created Name
+++ cisco:certification_topics:ccie-ei:1.1.bi [2025/12/03 10:17] (current) – Name
@@ Line 4: / Line 4: @@
   * No difference between any 17.9 - 17.18 versions
+[[https://www.youtube.com/watch?v=hrQff3fTViY|Charles Judd - Layer 2 Protocols]]\\
+=====CDP=====
+Cisco Discovery Protocol
+  * v2 enabled by default
+  * Hello time = 60s
+  * Hold time = 180s
+  * Cisco proprietary
+  * CDP messages are sent in clear text
+====Configuration====
+  * Set timer
+    * <code>sw(config)#cdp timer 80</code>
+  * Set hold time
+    * <code>sw(config)#cdp holdtime 240</code>
+  * Set to CDP v2
+    * <code>sw(config)#cdp advertise-v2</code>
+  * Disable CDP
+    * <code>sw(config)#no cdp run</code>
+  * Enable CDP
+    * <code>sw(config)#cdp run</code>
+  * Disable CDP per interface
+    * <code>sw(config-if)#no cdp enable</code>
+  * Enable CDP per interface
+    * <code>sw(config-if)#cdp enable</code>
+====Verifications====
+<code>sw#clear cdp ?
+  counters  Clear CDP counters
+  table     Clear cdp table</code>
+<code>sw#clear cdp counters</code>
+<code>sw#clear cdp table</code>
+<code>sw#show cdp ?
+  entry      Information for specific neighbor entry
+  interface  CDP interface status and configuration
+  neighbors  CDP neighbor entries
+  tlv        CDP optional TLVs
+  tlv-list   Information  about specific tlv list
+  traffic    CDP statistics
+  vlan       Limit CDP info to interfaces on a given vlan
+  |          Output modifiers
+  <cr>       <cr></code>
+<code>sw#show cdp entry ?
+  *     all CDP neighbor entries
+  WORD  Name of CDP neighbor entry</code>
+<code>sw#show cdp entry *
+-------------------------
+Device ID: sw-28.example.com
+Entry address(es):
+Platform: cisco C9300-24UX,  Capabilities: Switch IGMP
+Interface: TenGigabitEthernet1/0/18,  Port ID (outgoing port): TenGigabitEthernet1/0/18
+Holdtime : 175 sec
+Version :
+Cisco IOS Software [Fuji], Catalyst L3 Switch Software (CAT9K_IOSXE), Version 16.9.8, RELEASE SOFTWARE (fc4)
+Technical Support: http://www.cisco.com/techsupport
+Copyright (c) 1986-2021 by Cisco Systems, Inc.
+Compiled Wed 01-Sep-21 01:44 by mcpre
+advertisement version: 2
+Peer Source MAC: c4b3.6a02.a092
+VTP Management Domain: ''
+Native VLAN: 5
+Duplex: full</code>
+<code>sw#show cdp entry sw-28.example.com
+-------------------------
+Device ID: sw-28.example.com
+Entry address(es):
+Platform: cisco C9300-24UX,  Capabilities: Switch IGMP
+Interface: TenGigabitEthernet1/0/18,  Port ID (outgoing port): TenGigabitEthernet1/0/18
+Holdtime : 178 sec
+Version :
+Cisco IOS Software [Fuji], Catalyst L3 Switch Software (CAT9K_IOSXE), Version 16.9.8, RELEASE SOFTWARE (fc4)
+Technical Support: http://www.cisco.com/techsupport
+Copyright (c) 1986-2021 by Cisco Systems, Inc.
+Compiled Wed 01-Sep-21 01:44 by mcpre
+advertisement version: 2
+Peer Source MAC: c4b3.6a02.a092
+VTP Management Domain: ''
+Native VLAN: 5
+Duplex: full<code>
+sw#show cdp interface
+GigabitEthernet0/0 is administratively down, line protocol is down
+  Encapsulation ARPA
+  Sending CDP packets every 80 seconds
+  Holdtime is 240 seconds</code>
+<code>sw#show cdp interface TenGigabitEthernet1/0/1
+TenGigabitEthernet1/0/1 is up, line protocol is up
+  Encapsulation ARPA
+  Sending CDP packets every 80 seconds
+  Holdtime is 240 seconds</code>
+<code>sw#show cdp neighbors
+Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge
+                  S - Switch, H - Host, I - IGMP, r - Repeater, P - Phone,
+                  D - Remote, C - CVTA, M - Two-port Mac Relay
+Device ID        Local Intrfce     Holdtme    Capability  Platform  Port ID
+sw-28.example.com
+                 Ten 1/0/18        140              S I   C9300-24U Ten 1/0/18
+sw-28.example.com
+                 Ten 1/0/24        142              S I   C9300-24U Ten 1/0/24
+sw-28.example.com
+                 Ten 1/0/23        140              S I   C9300-24U Ten 1/0/23</code>
+<code>sw#show cdp neighbors Ten 1/0/18
+Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge
+                  S - Switch, H - Host, I - IGMP, r - Repeater, P - Phone,
+                  D - Remote, C - CVTA, M - Two-port Mac Relay
+Device ID        Local Intrfce     Holdtme    Capability  Platform  Port ID
+sw-28.example.com
+                 Ten 1/0/18        149              S I   C9300-24U Ten 1/0/18
+Total cdp entries displayed : 1</code>
+<code>sw#show cdp neighbors Ten 1/0/18 detail
+-------------------------
+Device ID: sw-28.example.com
+Entry address(es):
+Platform: cisco C9300-24UX,  Capabilities: Switch IGMP
+Interface: TenGigabitEthernet1/0/18,  Port ID (outgoing port): TenGigabitEthernet1/0/18
+Holdtime : 166 sec
+Version :
+Cisco IOS Software [Fuji], Catalyst L3 Switch Software (CAT9K_IOSXE), Version 16.9.8, RELEASE SOFTWARE (fc4)
+Technical Support: http://www.cisco.com/techsupport
+Copyright (c) 1986-2021 by Cisco Systems, Inc.
+Compiled Wed 01-Sep-21 01:44 by mcpre
+advertisement version: 2
+Peer Source MAC: c4b3.6a02.a092
+VTP Management Domain: ''
+Native VLAN: 5
+Duplex: full
+Total cdp entries displayed : 1</code>
+<code>sw#show cdp traffic
+CDP counters :
+        Total packets output: 159, Input: 202
+        Hdr syntax: 0, Chksum error: 0, Encaps failed: 0
+        No memory: 0, Invalid packet: 0,
+        CDP version 1 advertisements output: 0, Input: 0
+        CDP version 2 advertisements output: 159, Input: 202</code>
+======Backlinks======
+[[cisco:certification_topics:ccie-ei|CCIE-EI v1.1]]\\

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