let
    Owner = (ipAddress as text, subnetTable as table) as text =>
    let
        // Function to check if IP is in a single subnet
        IsIPInSubnet = (ip as text, subnet as text) as logical =>
        let
            // Normalize subnet to CIDR format if it's a plain IP address
            normalizedSubnet = 
                if Text.Contains(subnet, "/") then 
                    subnet 
                else 
                    subnet & "/32",
            
            // Split subnet into network address and CIDR
            subnetParts = Text.Split(normalizedSubnet, "/"),
            networkAddress = subnetParts{0},
            cidrMask = Number.From(subnetParts{1}),
            
            // Convert IP to integer
            IPToInteger = (ip as text) as number =>
                let
                    parts = Text.Split(ip, "."),
                    part1 = Number.From(parts{0}) * 256 * 256 * 256,
                    part2 = Number.From(parts{1}) * 256 * 256,
                    part3 = Number.From(parts{2}) * 256,
                    part4 = Number.From(parts{3})
                in
                    part1 + part2 + part3 + part4,
            
            // Convert IP to binary mask
            SubnetMask = (cidr as number) as number =>
                let
                    mask = Number.Power(2, 32) - Number.Power(2, 32 - cidr)
                in
                    mask,
            
            // Get network portion
            ipInt = IPToInteger(ip),
            networkInt = IPToInteger(networkAddress),
            mask = SubnetMask(cidrMask)
        in
            Number.BitwiseAnd(ipInt, mask) = Number.BitwiseAnd(networkInt, mask),
        
        // Filter table to find matching subnets
        matchingRows = Table.SelectRows(subnetTable, each IsIPInSubnet(ipAddress, [IP])),
        
        // Return owner if a match is found, otherwise return empty text
        result = 
            if Table.RowCount(matchingRows) > 0 then 
                matchingRows[Owner]{0}
            else 
                ""
    in
        result
in
    Owner