05-15-2018 01:26 PM - edited 03-08-2019 03:01 PM
Hello.
I´m having a problem with mi LAN becase i´m seeing with CDP devices that are not connected directly:
Device A ------ SW CISCO A------ SW CISCO B
I´m seeing the Device A with CDP in my SW B.
SW CISCO A#show ver
Cisco IOS Software, C2960 Software (C2960-LANBASEK9-M), Version 12.2(55)SE11, RELEASE SOFTWARE (fc3)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2016 by Cisco Systems, Inc.
Compiled Wed 17-Aug-16 13:46 by prod_rel_team
Image text-base: 0x00003000, data-base: 0x01900000
ROM: Bootstrap program is C2960 boot loader
BOOTLDR: C2960 Boot Loader (C2960-HBOOT-M) Version 12.2(44)SE6, RELEASE SOFTWARE (fc1)
Any idea of what is my problem??
Thank you.
Andrés.
05-15-2018 01:55 PM
05-15-2018 02:38 PM
05-15-2018 02:00 PM
Hello,
is this a live or a simulated network ? Post the output of 'debug cdp packets' ...
05-15-2018 03:42 PM
05-16-2018 06:14 AM
Well, what is Device A? What is it's MAC address?
From Cisco A and B can you provide:
#show mac address-table
05-16-2018 06:37 AM
05-16-2018 07:52 AM
I tried to disable CDP in one port and this is the result:
SWITCH A#show cdp nei fastEthernet 0/19
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
CVTA Fas 0/19 147 H Associate Port 2
SEP8851FB82428D Fas 0/19 86 H P Communica Eth 11
In SWITCH A i disable de CDP:
interface FastEthernet0/19
no cdp enable
cosabog13l2715#show cdp nei FastEthernet0/19
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
But in my SWITCH B, i´m still receiving the CDP of the Device that is connected to the Port 19 in SWITCH A.
COSABOG13SWL301#show cdp nei GigabitEthernet3/7 | i 428D
SEP8851FB82428D Gig 3/7 164 H P Communica Eth 11
05-16-2018 08:18 AM
05-16-2018 08:27 AM
Hello,
Yes, I clear the table in Switch B when I disable the CDP in Switch A
SWITCH B#clear cdp table
SWITCH B#clear cdp counters
SWITCH B#show cdp nei gi 3/7
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
CVTA Gig 3/7 179 H Associate Port 1
CVTA Gig 3/7 179 H Associate Port 2
A couple of seconds later...
SWITCH B#show cdp nei gi 3/7
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
CVTA Gig 3/7 179 H Associate Port 2
CVTA Gig 3/7 179 H Associate Port 1
SWITCH A Gig 3/7 175 S I WS-C2960- Gig 0/2
SEPD4C9EFDEBFD8 Gig 3/7 158 H P Communica Eth 11
SEP8851FB82428D Gig 3/7 145 H P Communica Eth 11 -------> Port Fa0/19 in SWITCH A
SEP40A8F0A3EDBD Gig 3/7 115 H P Communica Eth 10
SEPD4C9EFD4AEDD Gig 3/7 157 H P Communica Eth 17
SEPD4C9EFD62A1C Gig 3/7 168 H P Communica Eth 11
SEP40A8F0A3EDE9 Gig 3/7 157 H P Communica Eth 10
SEP40A8F0A3F295 Gig 3/7 145 H P Communica Eth 10
SEP40A8F0A4C164 Gig 3/7 155 H P Communica Eth 11
SEPD4C9EFD4AFD0 Gig 3/7 157 H P Communica Eth 11
SEP40A8F0A431C4 Gig 3/7 157 H P Communica Eth 10
SEPD4C9EFD4AE3E Gig 3/7 143 H P Communica Eth 11
SEPD4C9EFD6A310 Gig 3/7 158 H P Communica Eth 18
But in my Switch A CDP don´t show nothing...
SWITCH A#show cdp nei fa 0/19
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
SWITCH A#
Andrés.
05-16-2018 08:29 AM
you have physically verified the cabling between these switches ?
05-16-2018 08:49 AM
05-16-2018 08:58 AM
could you provide show run of both switches ?
05-16-2018 09:00 AM
This link doesn't specifically answer you question, but you may find it useful for some of the findings you have come across during the troubleshooting steps.
https://supportforums.cisco.com/t5/lan-switching-and-routing/cdp-neighbours/td-p/2485786
05-16-2018 10:15 AM
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