Where does pam_unix2.so come from?

["Thomas, Daniel J." <Daniel.Thomas@xxxxxxxxxx>]

Title: Where does pam_unix2.so come from?

I'm trying to install NIS+ on Red Hat 7.2.  I've installed the latest version of PAM that Redhat has complied for 7.2 from Red Hat's website, but I still don't have the pam_unix2.so in my /lib/security directory like the NIS+ How To describes using.  I think my version of PAM is 0.75-46.7.2.  Do I need to compile a newer version myself?

-Dan