We're a host catering to just ecommerce sites and consume an IPv4 address for each site specifically because of SSL certs. SNI (Server Name Indication) is what you're thinking of to let SSL send the hostname as the handshake process begins and does indeed eliminate the need for an exclusive IP (although there will always be a high rate of people who avoid shared IP's for SEO reasons since the search engines are doing nothing to eliminate that concern). The problem with SNI is many older, but still commonly used, browsers don't support it, such as IE on Windows XP, which certainly won't disappear long before address run-out is a distant memory.
My guess is amongst hosting providers, SSL is the cause for much of the usage; I have no feel for how may IP addresses are allocated towards hosts versus anything else though. David > -----Original Message----- > From: Jay Ashworth [mailto:j...@baylink.com] > Sent: Thursday, April 25, 2013 9:25 PM > To: NANOG > Subject: IPv6 and HTTPS > > Ok, here's a stupid question[1], which I'd know the answer to > if I ran bigger > networks: > > Does anyone know how much IPv4 space is allocated > *specifically* to cater > to the fact that HTTPS requires a dedicated IP per DNS name? > > Is that a statistically significant percentage of all the IPs in use? > > Wasn't there something going on to make HTTPS IP muxable? > How's that coming? > > How fast could it be deployed? > > Cheers, > -- jra > > [1] Ok, five questions. > -- > Jay R. Ashworth Baylink > j...@baylink.com > Designer The Things I Think > RFC 2100 > Ashworth & Associates http://baylink.pitas.com > 2000 Land Rover DII > St Petersburg FL USA #natog > +1 727 647 1274 > > >