I had this same issue and eventually used a lookup table for decimal (0-255) to Binary conversion. I called my lookup table Decimal_To_Binary with fields Decimal/Binary. I used MyIPNet to hold the static IPv4/netmask you want to convert. In general, this will be your input field. <main search> | eval MyIPNet="10.162.241.94/28" | eval MyIP=mvindex(split(MyIPNet,"/"),0) | eval MyNetMask=mvindex(split(MyIPNet,"/"),1) | eval MyIPSplit=split(MyIP,".") | eval IPPadding="00000000000000000000000000000000" | eval Octet1=mvindex(MyIPSplit,0), Octet2=mvindex(MyIPSplit,1),Octet3=mvindex(MyIPSplit,2),Octet4=mvindex(MyIPSplit,3) | lookup Decimal_To_Binary Decimal AS Octet1 OUTPUT Binary AS OutOctet1 | lookup Decimal_To_Binary Decimal AS Octet2 OUTPUT Binary AS OutOctet2 | lookup Decimal_To_Binary Decimal AS Octet3 OUTPUT Binary AS OutOctet3 | lookup Decimal_To_Binary Decimal AS Octet4 OUTPUT Binary AS OutOctet4 | eval BinaryIP=printf("%08d",OutOctet1)+printf("%08d",OutOctet2)+printf("%08d",OutOctet3)+printf("%08d",OutOctet4) | eval SubnetBinary=substr(substr(BinaryIP, 1, MyNetMask).IPPadding, 1, 32) | eval IPSubNet=tonumber(substr(SubnetBinary,1,8),2).".".tonumber(substr(SubnetBinary,9,8),2).".".tonumber(substr(SubnetBinary,17,8),2).".".tonumber(substr(SubnetBinary,25,8),2)."/".MyNetMask   ... View more