The SMB3 POSIX Extensions, a set of protocol extensions to allow for optimal Linux and Unix interoperability with NAS and Cloud file servers, have evolved over the past year, with test implementations in Samba and in the Linux kernel. These extensions address various compatibility problems for Linux and Unix clients (such as case sensitivity, locking, delete semantics and mode bits among others). This presentation will review the state of the protocol extensions, what was learned in the implementations in Samba and provide an opportunity for feedback and suggestions for future improvements to the POSIX extensions.