This would be completely mitigated by rolling out CG-NAT for all customers. Orange Espana has been working on this for their fibre customers (I think almost all of them are behind CG-NAT already), but ADSL customers are still waiting for it.
Also, CG-Nat is a HORRIBLE technology that causes lots of problems for subscribers all fo the sake of allowing an ISP to sell their IPV4 space off at a premium and pump up their numbers if a quarter demands it.
I'm with Virgin cable in the UK and they are going to IPv6 soon ... but with DS-Lite, so CG-NAT for IPv4 (yay, I can't connect back to my home VPN if I'm on an IPv4 only network) but native IPv6 (sort of yay).
You then also have the issues with online services, IP bans etc. etc. etc.
CG-NAT is nothing to be cheered on, and is worse than useless for "security".
I'm paying for internet service, I don't want some locked-down system that can't receive inbound connections.
So you trust the ISP to implement CG-NAT properly when they can’t manage to secure a simple CPE router?
CG-NAT has so many issues for consumers that will end up hoisted onto other services/applications support departments. The internet is not a one way street and there are many legitimate reasons for listening ports that I’m surprised anybody would push for CG-NAT.
I can’t even imagine trying to be get through to an ISP to fix their CG-NAT issue. It’s hard enough to get them to fix routing issues without being established on an industry mailing list or having an existing contact.
Nobody wants the AOL internet of yesteryear and IMO CG-NAT is just a step in that direction.