"chris" wrote

| It's easier to give everyone a unique IP address. Large scale NAT is
| called "Carrier Grade NAT" (CGNAT)

Ah. That's the term. I didn't know that. Looking
around online it looks like it's not so common, but I
didn't find definitive stats.

| If you look at webhosting options you'll see that
| a dedicated IP is sometimes an option. Probably the
| cheapo servers like Dreamhost don't even offer it.
| That limits how many customers they can have.
|
| Not really. Putting it another way, virtual hosting limits
| the number of IP address that are required.
|

That's saying the same thing. The number of IP
addresses they control is limited. If a host has a
block of 1,000 IP addresses they can host 1,000
sites, or they can do shared hosting and host any
number of sites. If you look at a place like
GoDaddy, their lower tier hosting is shared. For
$3/month they probably don't have an option,
and a lot of their hosting is for small businesses
that get no appreciable traffic.

|
| And IP4 addresses have already run out.
|
| No, they haven't.
| https://en.wikipedia.org/wiki/IPv4_address_exhaustion
|

Your link says they have.

| In fact,
| it's not unusual in my own web logs to see commercial
| GETs coming from numerous, similar IPs, even for one
| page and it's related images. And it's common (I don't
| know why) to see things like an IP that resolves
| to Brazil in terms of geolocation load a webpage,
| followed by an IP from Europe that downloads a linked
| file. Yet both show the same company in a hostname
| resolution.
|
| No idea what you're trying to say there.
|

I'm saying that a single visitor can have multiple
IPs. Search bots do that routinely. Here are some
other examples from my logs. I process them to resolve
hostname and geo-location. These were all single
visitors:

google-proxy-66-102-6-188.google.com.Mountain View-CA-US
google-proxy-66-102-6-186.google.com.Mountain View-CA-US
google-proxy-66-102-6-184.google.com.Mountain View-CA-US

bzq-82-80-249-143.dcenter.bezeqint.net.--Israel
bzq-82-80-230-228.cablep.bezeqint.net.Petah Tiqwa-HaMerkaz-Israel
bzq-82-80-249-164.dcenter.bezeqint.net.--Israel

115.239.212.134.Hangzhou-Zhejiang-China - -
115.239.212.139.Hangzhou-Zhejiang-China - -
115.239.212.134.Hangzhou-Zhejiang-China - -

I've also seen cases where remote locations share.
For instance, a visitor from Acme in one location visits
a page, but a distant location downloads the files.

Google proxy is an interesting one. I've been finding
it to be increasingly common, with several people
per day using it. Online I've found instructions for
using it to get around paywalls. But I suspect that what
I'm seeing is actually Google tracking people through
Chrome. In other words, Google seems to be acting
as a proxy server without asking, in order to track 100%
of Chrome users' activity.

Combining that with the fact that a company could
have one IP for numerous people, and people
behind routers in the same house will share IP,
the whole idea of paywalling by IP address doesn't
seem very realistic. But I don't know of any stats
about how common it is vs cookies vs possible other
methods.