Hi Sheng, Yes there is a formula, "As many as they need to address their hosts/interfaces." If you look at the arin website (www.arin.net) I believe you may find some guidelines. Bandwidth shouldn't be the driving factor but specific addressing needs should be. "ISP" can mean so many things these days:) If they have a 100 or so dial up ports and a dozen or so additional servers and hosts then a /24 should be more than enough. With 2Mb of transit they are not going to be any bigger than that? They may even get away with less addresses depending on what they're doing. JC -----Original Message----- From: owner-nanog@merit.edu [mailto:owner-nanog@merit.edu]On Behalf Of shsu@HydroOne.com Sent: Tuesday, June 12, 2001 1:17 PM To: nanog@merit.edu Subject: standards for giving out blocks of IP addresses Importance: High Hi, is there a standard or a practice on how much IP addresses an ISP should provide to his/her client given that this client has bought only 2Mb of bandwidth and this client is an ISP? Thanks sheng