4 ms·
The minimum subnet size in IPv6 is a /64 (18 quintillion IPs), and I think typically IPSs have been doing /56 delegation so you can have 256 of the /64 subnets.
by Bedon292 4y ago
The minimum subnet size in IPv6 is a /64 (18 quintillion IPs), and I think typically IPSs have been doing /56 delegation so you can have 256 of the /64 subnets. It means every device ever gets its own IP, and you never have to NAT anything anymore.
- elcritch 4y agoAssigning /64 subnets confused me for a long time with ipv6. It didn’t make sense. It clicked when I learned about some of the ways devices can get ipv6 ips. Those /64 subnets provide a large enough space for devices to randomly self-assign their own address without a high risk of collisions. https://datatracker.ietf.org/doc/html/rfc4193#section-3.2.1 https://datatracker.ietf.org/doc/html/rfc4193#section-3.2.1 All devices need to know is the prefix to generate their own a unique local address (ULA). This can provide for stable local IPs for a device too. This eliminates the need for dhcp since ipv6 provides a standard udp / icmpv6 based protocol for routers to announce the prefix. Icmpv6 also replaces arp so in all it’s a much more elegant system. It can be much more stable too.