Although the CkSFtp C++ Class Reference informs the existence of the member function "void put_ClientIpAddress(const char *newVal)", the following error ocurred while compiling: "Class does not have member function put_ClientIpAddress".
For FTP, the CkFtp2 Class reference is coherent. I use the put_ClientIpAddress function with no problem.
It should be there. If not, maybe you're using an old version?
If you find the newest version does not have it (which is very unlikely), please let me know what operating system, version of VC++, 32-bit or 64-bit, etc. that you are using and I'll double-check.