John Blakley Mon, 12/15/2008 - 06:46
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What are you needing this for? CDP is for Cisco devices to be aware of what other Cisco devices are connected to it, and it reports device type, port it's connected to, etc.

More information would be helpful on what you're needing to do.



kutukutu9 Mon, 12/15/2008 - 08:00
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Well you can't always determine what switch port a PC is plugged in to. If I could install a CDP client on the windows machine I'd have no issues knowing what switch they are plugged in to.

I know you can take the IP address of the PC and hunt down the MAC in your core with a "show ip arp | i "ip" - then get the port with "show mac-address-table | i "mac" identified by the show ip arp. BUT this doesn't always work and can be time consuming depending on the network.

John Blakley Mon, 12/15/2008 - 08:04
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Yeah, I have to agree on the time consuming part. I'm not sure anyone has a CDP client, but the thought of how you want to use it would be cool. I'd be interested if anyone has used anything like this, but I've never seen anything like it.


rwemisch Wed, 12/17/2008 - 13:02
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when all else fails, trace the cables...

cdp ttl=2 ... 1 hop ... means you still have to go each switch...

glen.grant Mon, 12/15/2008 - 16:38
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There appears to be a number of them just google windows cdp client .

kutukutu9 Tue, 12/16/2008 - 06:11
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If you have a very large network with many switches this is to cumbersome and at times does not work.

Only if:-

1) You have no IP subnet structure

2) You have not created an

Access <> Distirbution <> Core - switching topology

And it will always work if:-

1) The IP addres of the device is correct

2) The device is powered on

3) the device is connected to the network

4) it's been on-line for some time

5) You are looking for the device in the same logical broadcast domain (VLAN)

I find that I can find any IP address in my network (over 15 countries, over 500+ network devices, with over 5000+ users, 1000+ servers, and god only knows how may printers/IP photocopiers etc) from just receving the IP address, in about 2 minutes.

If your network is well planned and structured.


kutukutu9 Tue, 12/16/2008 - 07:00
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We do indeed have Access <> Distribution <> Core - switching topology and of course an ip subnet structure.

Always is a very strong statement. It doesn't always work for me. In one area particularly it hardly ever works. I have six 3750 switches stacked and the arp table seldom has the info I need for devices within that stack.

Below is the arp table for a site that currently has over 300 users all with the PC turned on right now...

3750-stack#show ip arp

Protocol Address Age (min) Hardware Addr Type Interface

Internet - 0024.a913.a240 ARPA Vlan1

Internet 137 0029.51a3.2cc0 ARPA Vlan1

Internet 0 002c.f190.c208 ARPA Vlan1

Internet - 0024.a1c3.a327 ARPA Vlan7

Internet - 0000.0000.0000 ARPA Virtual1

kutukutu9 Tue, 12/16/2008 - 06:13
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What is the name of this client? Who developed it?

There are many on "google" but I don't trust the source.




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