How to count cells excluding repeat info

[mwfernandez]

How do you create a formula or count information in a range of cells an
exclude any repeat information? For example, I have vulnerabilitie
listed in Column A and IP addresses listed in Column B. I want to b
able to count how many machines are in the spreadsheet or how man
vulernabilities.

Column A Column B
MS04-007 69.90.32.44
MS04-007 69.90.32.45
MS04-007 69.90.32.46
MS04-014 69.90.32.44
MS04-014 69.90.32.48
MS03-028 69.90.32.55
MS04-025 69.90.32.44
MS04-025 69.90.32.52

4 Vulnerabilities; 6 Machines

I would appreciate any help in this matter as it would stop me fro
counting all this manually. I have a spreadsheet currently with 45,00
rows

 

[Domenic]

Vulnerabilities...

=SUM(IF(A2:A1000<>"",1/COUNTIF(A2:A1000,A2:A1000)))

Machines...

=SUM(IF(B2:B1000<>"",1/COUNTIF(B2:B1000,B2:B1000)))

These formulas need to be entered using CONTROL+SHIFT+ENTER.

Hope this helps

 

[student]

These formulas need to be entered using CONTROL+SHIFT+ENTER.
What do you mean by that and how do you do it. I have seen this many times
in this group never got the purpose.

Thanks

 

[Gord Dibben]

See Chip Pearson's site for info on Arrays and the reason for
CRTL + SHIFT + ENTER

http://www.cpearson.com/excel/array.htm

Gord Dibben Excel MVP

These formulas need to be entered using CONTROL+SHIFT+ENTER.

What do you mean by that and how do you do it. I have seen this many times
in this group never got the purpose.

Thanks