IP Scheme Excel Sheet

[cravix]

The company i support has standardized IP schemes, IE the server for each site always ends in the same octet, workstation 1 for each site ends in the same and so on, what id would like to create is a sheet where a user can put in the ip for the server and it figures all the other IPS out, so say the ip for the server is 10.1.1.50, I need a formula to say calculate the 3rd octet +1 and the 4th octet be 109 so the ip is 10.1.2.109, I have several variations similar to this,

 

[navic]

I need a formula to say calculate the 3rd octet +1 and the 4th octet be 109 so the ip is 10.1.2.109,

If I understood you well, try in A1 cell and copy down

="10.1."&ROWS($A$1:A1)&".109"