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MAC Address Query

Created: 21 Mar 2011 • Updated: 21 Mar 2011 | 2 comments
GOC's picture
This issue has been solved. See solution.

Hi guys,

I'm creating inventory reports which includes Mac address in one of the columns. The organisation which i'm working for is toying with the idea of Asset Tagging all devices (PC's, Servers, Laptops) with the last 4 digits of the devices MAC address, so that it can also be linked to the Altiris database when logging a call against it.

Does anyone know if the last 4 digits in the Mac address is always unique, or do you know how I can compare / search for this in excel?

I currently have an excel report extracted but it's only showing me duplicates of the whole mac address (where pc's have been rebuilt), but not specifically to the last four digits...

Were were originally going to use the serial numbers but have discovered on Dell serial numbers, that the last four digits are often the same (with the first 3/4 bieing unique, and HP is vice versa...

Any help appreciated.



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mclemson's picture

I'm guessing that you can't use more than 4 characters.  Obviously the entire Dell Service Tag is unique, and this would be the best way to go.  MAC address is apt to change when parts get replaced or when a different network device is in use.

Using a small sample from one of my environments (700 Dell nodes), I found 4 duplicates in the first four characters as well.

If you had a report from Altiris listing MAC addresses, and wanted to compare it in Excel, and all of your MAC addresses were in Column A, I would do it thus:

  • Assuming you have headers, row 1 is occupied by headers
  • Starting in cell B2, type the formula =RIGHT(A1,4)
  • Fill this cell down to the end of column B
  • Column B is now populated with the last 4 characters of the MAC address
  • Sort Column B alphabetically (Z to A)
  • Starting in cell C3, type the formula =IF(B2=B3,"Error: duplicate","")
  • Fill this cell down to the end of Column C
  • Column C is now populated with the message "Error: duplicate found" if a duplicate is found if the last 4 of any particular MAC address is found elsewhere on the list

Alternatively, after filling Column B but before sorting, highlight the column and choose 'Remove duplicates,' which will tell you how many duplicates were found.  I prefer this method since it lets me identify where the duplication exists.

Does this help?

Mike Clemson, Senior Systems Engineer, ASC
Intuitive Technology Group -- Symantec Platinum Partner

GOC's picture

thanks mclemon,

I tried this and found several duplicates across our estate (approx 6,000 pc's, laptops HP & Dell). there goes that idea!