Whitelisting inboud subnet range in F5 using irule

You can just see the article How to match subnet of the client IP in iRule (f5.com) an better use data groups (class (f5.com)). Also better log outside of the "if else" the client IP address that the F5 device sees as if there is proxy or nat device before the F5 device it  is normal that TCP ip address will not match and better try adding XFF header and matching it.

Solved: IP Filtering using Xff-clientip in iRule - DevCentral (f5.com)