Final answer:
ISPs generally assign public IPv6 blocks as /64 network masks, which allow for a vast number of unique addresses, suitable for most customers including residential and small businesses. This subnet size supports important IPv6 features.The statement is true.
Step-by-step explanation:
The question asks whether ISPs assign public IPv6 blocks as /64 network masks. The answer is true. Generally, when ISPs allocate IPv6 address space to end-users, they provide a /64 subnet. This /64 addressing allows for 18,446,744,073,709,551,616 unique IP addresses, which is ample for most deployment scenarios, including residential and small business customers.
In larger enterprise networks, ISPs might allocate larger blocks, such as a /48, which subdivides further into multiple /64 subnets. The /64 network mask is considered the standard subnet size for IPv6, as it facilitates optimal operation of certain IPv6 features such as stateless address autoconfiguration (SLAAC) and neighbor discovery protocol (NDP).