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New Member

CDP is showing the wrong information.

Hi All,

I'm practicing for my CCNA. Now i'm analysing the CDP.

My topology has a router and 2 switches as shows below.

Capture.PNG

Here i configured the Fa0/2 ports on both switches to be half-duplex. But the "show cdp entry *" is showing that the port is operating in an full duplex mode.

Here is the confirmation that i configured fa0/2 on both switches as half-duplex:

Truncated output from switch0:


switch0#show interfaces fastEthernet 0/2

FastEthernet0/2 is up, line protocol is up (connected)

  Hardware is Lance, address is 00d0.ba12.5102 (bia 00d0.ba12.5102)

BW 100000 Kbit, DLY 1000 usec,

     reliability 255/255, txload 1/255, rxload 1/255

  Encapsulation ARPA, loopback not set

  Keepalive set (10 sec)

  Half-duplex, 100Mb/s

  input flow-control is off, output flow-control is off

Truncated output from switch1:

switch1#show interfaces fastEthernet 0/2

FastEthernet0/2 is up, line protocol is up (connected)

  Hardware is Lance, address is 00e0.8f36.6502 (bia 00e0.8f36.6502)

BW 100000 Kbit, DLY 1000 usec,

     reliability 255/255, txload 1/255, rxload 1/255

  Encapsulation ARPA, loopback not set

  Keepalive set (10 sec)

  Half-duplex, 100Mb/s

  input flow-control is off, output flow-control is off

Here is the output from switch0 for "show cdp entry *" command:

Truncated o/p:

switch0#show cdp entry *

Device ID: switch1

Entry address(es):

  IP address : 10.11.12.253

Platform: cisco 2960, Capabilities: Switch

Interface: FastEthernet0/2, Port ID (outgoing port): FastEthernet0/2

Holdtime: 144

Version :

Cisco IOS Software, C2960 Software (C2960-LANBASE-M), Version 12.2(25)FX, RELEASE SOFTWARE (fc1)

Copyright (c) 1986-2005 by Cisco Systems, Inc.

Compiled Wed 12-Oct-05 22:05 by pt_team

advertisement version: 2

Duplex: full                         //whereas it has to be half //

---------------------------

Thanks in advance for help.

Regards,

Chandu

Regards, Chandu
Everyone's tags (1)
2 ACCEPTED SOLUTIONS

Accepted Solutions
Hall of Fame Super Gold

CDP is showing the wrong information.

Chandu,

That's one of the biggest problems with simulators when it comes to discrepancies.

Hall of Fame Super Gold

CDP is showing the wrong information.

In real switches, "sh cdp neighbor" will give you good details better than simulators.  Even old switches like 2900XL/3500XL are very good studying tools for your certification.  You can get working 2900XL/3500XL cheaply from e-bay.

8 REPLIES
Hall of Fame Super Gold

CDP is showing the wrong information.

Chandu,

That's one of the biggest problems with simulators when it comes to discrepancies.

New Member

CDP is showing the wrong information.

Thanks Leo.

But can you let me know whose duplex settings will "show cdp entry * " command shows.

Here in this case will it shows the duplex setting of switch0's interface or switch1's interface ?

Regards,

Chandu

Regards, Chandu
Hall of Fame Super Gold

CDP is showing the wrong information.

In real switches, "sh cdp neighbor" will give you good details better than simulators.  Even old switches like 2900XL/3500XL are very good studying tools for your certification.  You can get working 2900XL/3500XL cheaply from e-bay.

New Member

CDP is showing the wrong information.

Will there be any question regarding CDP in the ccna exam ?

Regards, Chandu
Hall of Fame Super Gold

CDP is showing the wrong information.

Will there be any question regarding CDP in the ccna exam ?

Depends on your "luck".  You will get any random questions from the Cisco database.

New Member

CDP is showing the wrong information.

Finally, will i pass CCNA with PT ?

Because i cannot offer a real equipment.

Regards,

Chandu

Regards, Chandu

Re: CDP is showing the wrong information.

Hi,

Yes, you can pass CCNA R/S with PT. There's already a version 6 released which includes ISR G2 routers running IOS 15.0.

I would stay away from "XL" switches as they're limited with commands that it supports.

Sent from Cisco Technical Support iPhone App

New Member

CDP is showing the wrong information.

Thanks for you feedback.

Regards,

Chandu

Regards, Chandu
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