There are possible operational security gains that can be permitted by ipv6, if operations groups permit... For example, because of NAT and dynamic ip addrs al

There are possible operational security gains that can be permitted by ipv6, if operations groups permit... For example, because of NAT and dynamic ip addrs allocation, my VOIP provider pretty much has to accept any ipv4 address in the world. My ISP's allocations are numerous and non-contiguous and my RFC1918 LAN address is meaningless from a security perspective. So anyone on the planet can log into my VOIP provider as if they're me, if they obtain my login info. That's kind of dumb. However, with ipv6, with significant operational changes, it would be trivial to set up my account and firewall such that my VOIP device only talks to one specific providers /128 and my provider's account and firewall will only talk to my one very specific /128. Yeah yeah there are load balancing issues and device replacement issues such that a sane provider would operate on /64 sized networks both at their data center and my house, not individual devices. But it would be immensely more secure than ipv4, anyway. There are other operational advantages. Currently with ipv4 companies usually don't have "an allocation" they have many, maybe dozens of little /27 here and a /28 there as they added devices. In the ipv6 world of the future companies will get a single /56 or maybe a /48 and call it good. So you get DDOSed or attacked or whatever, there's exactly one address range to block. Not 50 little ones depending on random DHCP address assignments. It'll be a much faster and simpler world. Doing egress filtering? They'll be one block to permit, thats all. Just one rule, not 75.