MAC Address Table - Showing Devices On All Switch Tables

[mmickells]

GOAL:

We are slowly moving to Cisco Meriaki gear, but first need documentation on who has what connected where. So I'm attempting to create some documentation that shows me what devices are connected to each switch and who they belong to. (Example: I'd like to know that Susie has a phone, computer, and printer on switch ports 20, 21, 22.)

EXPLANATION:

My idea was if I had a list of computer, servers, phones, printers, and other network devices which also includes the MAC Address and who used the device I could compare with the switches MAC Address Table.

The issue I've ran into is with getting a good MAC Address Table list from the switches. I'm able to get the table, but I'm getting lots of duplicate addresses.

For example, say in Building 1, 00:AA:BB:CC:DD:EE is physically attached to Switch 1, Port 12. When I run the command to get the address table on Switch 1 the MAC shows up just as expected. However, if I go over to building 3, Switch 5 and run the table command the same "00:AA:BB:CC:DD:EE" MAC Address shows up on this switch too. Unusually it on like a management port so my assumption is it's seeing connections from other switches, maybe due to trunking for VLAN's? The problem with this is in my case I don't know what's connected where. So it's harder for me to determine where the device is "really" connected when the same address shows up on all 6 switches.

QUESTION:

I need "clean" data for my database which is currently throwing errors because of all the duplicates. I've tried just deleting the duplicates, but then I'm left with a much smaller list that doesn't match what's plugged into the switches. (Example, one one switch I removed duplicates and ended up with like 7 entries left, but all 48 ports are connected. Sure some devices could be offline at that moment, but it's not 30-40 devices offline)

Is there a way to get a MAC list from a device that shows ONLY what is currently connected to that switch?

Thanks In Advance!

mmickells

[acampbell]

Hi,

If you find out whic port/interfaces are your uplinks you can exclude these port from your mac address table search

sh cdp nei | ex SEP|ATA

this will show all neighbors except CISCO PHONES/ATAs

Now you can add the uplink ports as exclusions to your MAC search - something like this

sh mac add | ex CPU|1/1/1|1/1/2

This would exclude my local CPU and my interfaces gig1/1/1 & gig 1/1/2

[mmickells]

Thank you for the response! The commands you provided helped me better understand which ports were "up-link" ports. Plus with excluding the CPU entries it really cleans things up!

[luis_cordova]

Hi @mmickells ,

Maybe this discussion can give you some help:

https://community.cisco.com/t5/small-business-switches/view-device-ip-mac-information-connected-to-a-specific-port/td-p/2765092

Regards

[mmickells]

Thank you for the link. I was also able to find useful commands they listed as well.