Your company is designing its network. The network will use an IPv6 prefix of 2001:DB8:BBCC:0000::/53.
You need to identify an IPv6 addressing scheme that will support 2000 subnets.
Which network mask should you use?
A.
/61
B.
/62
C.
/63
D.
/64
This is kind of a trick question. IPv6 simply does not use any size-limiting subnet-mask-constructions anymore. In IPv6 subnets are always handled with a standard /64 mask. See http://www.netbsd.org/docs/network/ipv6/ . In additiona RFC4291 compliant subnets are always using 64 bits for the host, leaving 64 (/64) bits for the network part. See this article for more input: http://en.wikipedia.org/wiki/Subnetwork#IPv6_subnetting