This problem is present in the latest release of RawHide, both in the i386 and sparc architectures. When you try to telnet or ftp into the machine with the problem, the client program respond with the message no network ports available. While in X windows, when trying to open an xterm a "no pty available" message pops in the console.
Already solved in bug 2169! The problem is solved by adding an entry for /dev/pty on /etc/fstab: none /dev/pts devpts mode=0622,gid=5 0 0 This is either a bug or a security feature in rawhide, but I thinks it is probably a bug since it even prevent you from opening xterms in X windows.
*** This bug has been marked as a duplicate of 2169 ***