11-05-2008 12:55 AM - edited 03-06-2019 02:19 AM
Hi,
Can we discover two different devices through CDP on a same port? Please find the output below:
CHBNBAN2_2950A#sh cdp neighbors
Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge
S - Switch, H - Host, I - IGMP, r - Repeater, P - Phone
Device ID Local Intrfce Holdtme Capability Platform Port ID
CHBNBAN4_4506A Gig 0/1 144 R S I WS-C4506 Gig 2/4
CHBNBAN2_2950C Gig 0/2 177 S I WS-C2950G-Gig 0/1
CHBNBAN2_2950B Gig 0/2 172 S I WS-C2950G-Gig 0/1
CHBNBAN2_2950A#
Thanks and Regards,
Mayank Nauni
11-05-2008 01:01 AM
Mayank
CDP is a layer 2 protocol
If your Cisco devices are connected to a Hub
then all the devices will be discovered.
Mark
11-05-2008 01:04 AM
Thanks for your response Mark, but there is not Hub over there⦠I've confirmed the same from my counterpart. And one more query... using a hub will hamper the network performance... isn't it?
Thanks :)
11-05-2008 01:17 AM
are the 2950C and B clustered ? (managed by one single IP address)
11-05-2008 01:27 AM
Good point
Are the switches connected via Giga-stack connectors
detailed here
http://www.cisco.com/en/US/products/hw/modules/ps872/products_data_sheet09186a00800a1789.html
11-05-2008 02:17 AM
Thanks ohassairi and Mark... will check and revert...
:)
11-05-2008 04:15 AM
As a previous poster said I would venture to guess the 2950's are setup as a cluster or are tied together using stack ports ,you will see this type of dsiplay if that is the case.
11-05-2008 08:26 AM
The symptom will also happen if the devices are connected by a switch that is not a Cisco switch. If CDP frames are sent and received by a Cisco switch then the switch just processes it, you will see the switch but not see anything connected through it. But if the switch is not a Cisco switch then it does not recognize CDP and will flood the CDP frame through all of its other interfaces and you could easily see multiple devices as connected on one interface of your Cisco device.
Perhaps Mayank can tell us what kind of device is connected on Gig0/1 of CHBNBAN2_2950A?
HTH
Rick
11-06-2008 12:48 AM
Hi Rick,
It's a Cisco 4506 ( output is attached in the first post)
Thanks,
Mayank Nauni
11-06-2008 04:22 AM
Mayank
Thank for for this. Could you also tell us what is physically connected on Gig 0/2?
HTH
Rick
11-06-2008 04:48 AM
HI Rick,
CHBNBAN2_2950C Gig 0/2 177 S I WS-C2950G-Gig 0/1
CHBNBAN2_2950B Gig 0/2 172 S I WS-C2950G-Gig 0/1
These are two different C2950G Switches..
Thanks and Regards,
Mayank Nauni
11-06-2008 05:47 AM
Mayank
This is the CDP output which tells us what is logically connected to the interface. I would like to know what is physicall connected to Gig0/2 of CHBNBAN2_2950A.
HTH
Rick
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide