One problem with excessively large fields, including variable length addresses with a high maximum length, is that the next time someone wants to encode some additional information, they just tuck it inside that field in some quasi-proprietary way, instead of going to the trouble of actually adding a field. Witness X.509 Certificate "serial numbers", which are arbitrary precision integers, but which frequently are used for a variety of information, all BER encoded... Thanks, Donald ============================= Donald E. Eastlake 3rd +1-508-333-2270 (cell) 155 Beaver Street, Milford, MA 01757 USA d3e3e3@xxxxxxxxx On Fri, Aug 10, 2012 at 1:35 PM, David Conrad <drc@xxxxxxxxxxxxxxx> wrote: > On Aug 10, 2012, at 10:22 AM, "Andrew G. Malis" <agmalis@xxxxxxxxx> wrote: >> Another alternative is self-describing variable-length addresses, >> again do it once and we'll never have to worry about it again. > > Heretic! That's OSI speak! Why do you hate the Internet you ISO/ITU lackey?!? > > </flashback> > > Yeah, variable-length addresses would have been nice. There was even working code. Maybe next IPng. > > Regards, > -drc >