I have recently moved and went from Coaxial (Xfinity) to Fiber (BrightRidge), I seem to have 1 problem, checking my wan interface/upstream details, it shows me
7: wan: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
link/ether a4:**:**:**:**:36 brd ff:ff:ff:ff:ff:ff
inet 100.65.***.***/19 brd 100.65.159.255 scope global wan
valid_lft forever preferred_lft forever
inet6 fe80::a697:33ff:fedf:9836/64 scope link
valid_lft forever preferred_lft forever
But when I do something like curl ip.me, I get 152.**.**.7, This is irregular from what I'm used to, most ISPs gave me the right wan ip so not sure if this is normal. They installed an ONT, not sure if the ONT is messing with it (should be a level 2 device so shouldn't mess with ip addressing?) or if this is what a direct connection is like (with coax, they'd always give a 3 in 1 and I'd put it in bridge mode). The reason the wan interface's ip matters to me is I'd prefer to not rely on something like curling ip4.me to check if my ip has changed (with most dynamic ips I have had, it is rare even with a power outage but nice to have automated just in case). I have also checked the premade functions/scripts for grabbing gateway and address, address returns the 100.65.***.*** and gateway returns nothing. Worst case I do need to curl ip4.me but this did also intrigue me to see different upstream/addressing than I am used to.
This is CGNAT, where the ISP NATs multiple customers out to one real IP. The 100.X IP is a private reserved range intended for use by ISPs. It is not routable on the Internet and as with most NAT, incoming connections are not possible.
Ah, that explains so much, I looked up the ip on ip lookup, nothing, asn, no asn, and was confused, and also makes sense why they said I could pay for a dynamic ip xD, I have never had CGNAT, thought dynamic was par for the course, had heard of people having CGNAT, but especially when you are rolling out expensive infrastructure like Fiber, didn't even occur to me that CGNAT would ever cross their minds xD. Thank you for clearing that up!!!!
Many ISPs with cgNAT also offer IPv6 connectivity, which might be 'good enough' for your needs of incoming connections.
Personally I'm in such a situation (except that my ISP doesn't even offer a dynamic IPv6 address at all, they can't, with 32'768 for over a million customers) as well, so I do resort to IPv6 wherever possible (wireguard works quite nicely over an IPv6 endpoint).
Oh yeah, sadly they said they don't have ipv6 on the first phone call and saw their ASN has 0 ipv6 addresses at least according to one site, little sad as I have my stuff setup for ipv6 as well as ipv4 but not a big deal, there is also 4to6 tunnel brokers iirc so that could be an option