On Fri, 5 Dec 2008, Keith Moore wrote: > Stephane Bortzmeyer wrote: > > > > For a good part, this is already done. You cannot use IP addresses for > > many important applications (the Web because of virtual hosting and > > email because most MTA setup prevent it). > > you're generalizing about the entire Internet from two applications? It's a general truth that application protocols need a layer of addressing of their own, and it isn't sufficient to just identify the host the application is running on. The special cases are the applications that do not need extra addressing. In the cases where protocols do not support their own addressing architecture, we have usually been forced to retro-fit it or bodge around it. For example, the HTTP Host: header, the TLS server_name extension, the subjectAltName x.509 field, the use of full email addresses instead of usernames as login names for IMAP and POP. XMPP got this right. Tony. -- f.anthony.n.finch <dot@xxxxxxxx> http://dotat.at/ VIKING NORTH UTSIRE SOUTH UTSIRE FORTIES CROMARTY FORTH EASTERLY OR NORTHEASTERLY 5 OR 6, OCCASIONALLY 7 OR GALE 8 AT FIRST EXCEPT IN NORTH UTSIRE AND FORTH, BACKING NORTHERLY OR NORTHWESTERLY AND DECREASING 4 AT TIMES. MODERATE OR ROUGH, OCCASIONALLY VERY ROUGH AT FIRST EXCEPT IN NORTH UTSIRE AND FORTH. SQUALLY SHOWERS. MODERATE OR GOOD. _______________________________________________ Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf