New(ish) to the finer behavioral traits of samba(4)? When you do excute rpm -qa samba, it should reveal samba series 4. It does on my Fedora system. Now you get the error message when trying to access samba server using smbclient:

protocol negotiation failed: NT_STATUS_IO_TIMEOUT

Sucks doesn’t it?

The solution is simple, make sure that there is a mapping between your IP address and $HOSTNAME in /etc/hosts.