Keith, as one thinks about VPNs, tunneling, mobility and the like, assuming a week is probably a bad idea. Think a bit about the way AOL's IM tracks the binding of an IM handle to an IP address - it is quite dynamic. Vint At 05:07 PM 8/28/2003 -0400, Keith Moore wrote: >IMHO, apps should be able to assume that an advertised address-host >binding is valid for a minimum of a week. This is a minimum - it >should be longer whenever possible. (however there's no requirement to >maintain addresses longer than the nets will be accessible anyway - >i.e., you don't expect the addresses for the ietf conference net to >remain valid after the net is unplugged...but they shouldn't be reused >within a week either.) Vint Cerf SVP Technology Strategy MCI 22001 Loudoun County Parkway, F2-4115 Ashburn, VA 20147 703 886 1690 (v806 1690) 703 886 0047 fax vinton.g.cerf@mci.com www.mci.com/cerfsup