You often can just tell the ISP you're using your own router, or use bridging, or to use double NAT in the worst case (best avoided, but sometimes it's necessary to have routing freedom).
@sallyNULL >ISPs do not like to disclose PPPoE credentials I haven't run into this yet myself, but nowadays I would probably go and crack that router open and see if I can find a UART header to access a command line, or if that fails, dump the NAND with a NAND dumper and then look for the credentials.
I've found that NAT hole punching nowadays barely works for p2p provided other hosts aren't NATed (i.e. at least one other client is binded to a port-forwarded port).
Really, we've needed IPv6 since 30 years ago, but noooo.
> You often can just tell the ISP you're using your own router, or use bridging, or to use double NAT in the worst case (best avoided, but sometimes it's necessary to have routing freedom).
You can tell them but they won't care, from my own experience, ISPs do not like to disclose PPPoE credentials which are needed to replace the router. And you're already in a multi layer NAT by default with these dogshit providers, free software that relies on p2p doesn't work.