IPv6 is upon us, well soon anyways and there has been much confusion about IPv6. This post will hopefully clear up some of this confusion. This post assumes that IPv4 doesn’t bother you.
IPv6 address look like such:
1234:5678:90AB:CDEF:1234:5678:90AB:CDEF
8 Sets of 4 hexdecimal numbers (0-F) By standard, first four sets of numbers is reserved for network part and last 4 sets of number is reserved for the hosts inside the network. Example, your ISP would give you IP of 2607:f0d0:54fc:4564 giving you last 4 group for your network around 18 trillion address per network.
You can shorten an IPv6 by putting :: between a string of zeros but only once. Example, 1234:1234:0000:0000:0000:0000:0000:ABCD would be shorten to 1234:1234::ABCD. However, 1234:1234:0000:0000:ABCD:0000:0000:9999 could NOT be shorten to 1234:1234::ABCD::9999 Only 1234:1234::ABCD:0000:0000:9999 or 1234:1234:0000:0000:ABCD::9999
Biggest change for most admins is subnet mask has been replaced with Subnet Prefix length which is basically Subnet Mask replaced with / identifier similar that 192.168.1.0/24
Here is table of subnet prefixes:
| 1234:: | /16 |
| 1234:5678:: | /32 |
| 1234:5678:90AB:: | /48 |
| 1234:5678:90AB:CDEF:: | /64 (standard) |
| 1234:5678:90AB:CDEF:1234:: | /80 |
| 1234:5678:90AB:CDEF:1234:5678:: | /96 |
| 1234:5678:90AB:CDEF:1234:5678:90AB:: | /112 |
| 1234:5678:90AB:CDEF:1234:5678:90AB:CDEF | /128 (Single IP) |
DNS
DNS remains the same except A record become AAAA records. Past that, everything remains the same. However, due to complexity of IPs, DNS is critical to get working.