Basically what the title says - Can my ISP see the exit node of my VPN ? I hope not, because that would be weird, and would defeat the whole purpose of a VPN.
A bit of backstory about why I had this question ( it is slightly long, so is totally okay for the reader to skip this part )
My partner subscribed to a McAfee security suite, that we share (because they had some promotions available or something for multiple devices). It's not the worst thing around - the antivirus part, but it also came with their "McAfee Safe Connect VPN" service, which is infamous for having a super-invasive data logging policy. So I said fuck'em and set out for a better option.
I am more or less tech-literate, but I researched somewhat deeply this time, basically to choose between "Privacy" (like Bruce Wayne - everybody knows who he is and lives in the Wayne Manor, but nobody knows what he does there, or that he has a BatCave underground), and "Anonymity" (Like Batman - everybody knows what he does - kicks ass of bad guys - but nobody really knows who he is, ok except for may be a couple of people) - basically trying to figure out if I needed a VPN at all or not.
I already have DNS-over-HTTPS enabled in all my devices - so that kinda took care of my "privacy" concerns (i.e. a nosy ISP) - although I believe my ISP can see which IP/Domain I am finally connecting to, which kinda sucks.
Apart from my ISP, the other concern was Public Wi-fi. I do work with my device(s) on-the-go a lot, which is why I have reason to ensure safety while connected to Public Wi-fi at Cafes/Restaurants/Airports. The fact that Internet is not just HTTPS - there's telnet/FTP/SMTP/IMAP/POP3/Gopher and other protocols which have their own encryption methods (or not) also led me to the realization that DOH is not a total replacement for VPN. And the ISP can know my destination Domain even if DOH stops them from sniffing or blocking the DNS lookup itself.
In the end, I decided to go with VPN. Not any free ones (because as we all know they suck), and neither any over-promoted ones as well, like Nord or IPVanish (because they suck as well, in a different way). I chose Mullvad, but white labeled as Mozilla VPN. This is because I do use email-forwarding services to a large extent, and Mozilla is providing this combined deal of their email masking service Firefox Relay along with phone masking and VPN for 5 devices, all for a reasonable subscription (I won't say how much because this post is not a promotion for them) - and being a long-time Firefox user (and also being anti-Google for a while), I decided to go with that (and so far all I heard about Mullvad are good things).
So far I am alright with it. Let's see how it goes.
And that concludes my VPN journey story. While I was researching about how much my ISP can see when I connect to a VPN - I found that they can see encrypted traffic to and from my real IP, and that I connected to a "VPN server", and nothing else.
I assume this "VPN Server" that they can see is the "entry node", and not the "exit node" (i.e. my IP as seen by the world) - but never got a clear answer to that - which led me to my original question above.
And thanks for reading this far ! Feel free to share insights.
Traditionally, the entry node and the exit node have been the same VPN server/ip. In that sense, your ISP does know the IP of your exit server, since they are the ones connecting you to it.
For example, your X ISP's logs could show "At 15:00, user #123 connects to IP 1.2.3.4, which lookup shows is assigned to "CheapVPNs Ltd". At 15:01 our email server received 1,000,000 emails from IP 1.2.3.4 all angrily complaining about how "X ISP sucks". Correlation implies user #123 is responsible for the mail bomb attack against our servers."
At the moment, Mullvad specifically does use different entry and exit IPs, but they are all still located in the same datacenter and subnet. That is, you could be connecting to a Mullvad VPN server 1.2.3.4, 1.2.3.5, or 1.2.3.6 in London, and they all exit out through 1.2.3.1 in London. This is just something Mullvad does. Other VPN services may not do it and Mullvad hasn't done it in the past. Someone analyzing ISP logs could correlate these IPs if they really wanted to.
Mullvad also offers "multihop", but the way they have it implemented currently (changing the destination port number), an ISP could still deduce your exit IP if they bother looking up records of Mullvad network structure (which are publicly available), since they know the IP number and the port number of your entrance node.
The only way to hide your VPN exit IP from your ISP currently is to use multiple VPN services and nest them inside each other (or use one service and nest it inside itself using the "multiple devices" perk). Then only a state-level actor could hope to correlate your traffic by monitoring the ingress/outflow of multiple IPs simultaneously.