+.B exportfs
+and it's partner program
+.B mountd
+work in one of two modes, a legacy mode which applies to 2.4 and
+earlier versions of the Linux kernel, and a new mode which applies to
+2.6 and later versions providing the
+.B nfsd
+virtual filesystem has been mounted at
+.B /proc/fs/nfsd
+or
+.BR /proc/fs/nfs .
+If this filesystem is not mounted in 2.6, the legacy mode is used.
+.P
+In the new mode,
+.B exportfs
+does not give any information to the kernel but only provides it to
+.B mountd
+through the
+.B /var/lib/nfs/xtab
+file.
+.B mountd
+will listen to requests from the kernel and will provide information
+as needed.
+.P
+In the legacy mode,
+any export requests which identify a specific host (rather than a