> A number of IETF documents(*) state that there are some service providers
> that place a NAT box in front of their entire network, so all their
> customers get private addresses rather than public address.
> It is often stated that these are primarily cable-based providers.
> I am trying to get a handle on how common this practice is.
It's not uncommon among smaller providers in developing countries.
International transit providers, particularly those that use satellite for
"local loop" seem to be pretty miserly with IP addresses, leading their
customer-ISPs to use NAT more broadly than is healthy. Obviously this
makes it very difficult to multi-home, which reinforces the upstream's
position.
-Bill
