> An expression of the form 'n.n.n.n/m.m.m.m´ is interpreted as a > 'net/mask´ pair. An IPv4 host address is matched if 'net´ is equal > to the bitwise AND of the address and the 'mask´. For example, > the net/mask pattern '131.155.72.0/255.255.254.0´ matches every > address in the range '131.155.72.0´ through '131.155.73.255´. > > > Is there any reason why it must be written out as: > > 131.155.72.0/255.255.254.0 > > ... as opposed to using the shorter version: > > 131.155.72.0/23 At one point it was possible to create a non-contiguous mask. This would not be doable with the short / notation. I've never actually used a non-contiguous mask, but there's a whole chapter on it in one of my earlier networking books. -- * The Digital Hermit http://www.digitalhermit.com * Unix and Linux Solutions kwan@xxxxxxxxxxxxxxxxx