When the ipv4 address was not enough, Ipv6 was introduced. Universities can use ipv6 addresses, because your university's network equipment supports dual stack, that is, it supports ipv4 and ipv6. Your home broadband needs an ipv4 address, and you can't get ipv6 resources. I usually popularize new things on the university campus first. At present, ipv6 addresses are only used for educational networks composed of campus networks. Telecom, Netcom and similar small operators have not been widely used. Of course, there are some tunnel-like technologies to solve the communication problem between ipv4 and ipv6, but they are rarely used.