IPV6 Global Unicast prefix address--GURU TIME!

mikeybinec

OK, the address 2000::/3 has a range from 2000 - 3FFF

I can't figure how that range goes up to 3FFF. Can we get a guru to explain it? Why not 5FFF?

Thanks

Switch1

I'm no guru, but I've been reading about IPv6 this week and suppose I could provide some insight.

The /3 prefix length means that only the first 3 bits are significant when it comes to matching the prefix 2000. The first 3 bits of the first hexadecimal value 2 are 001x. The fourth bit, x, is insignificant and can be either 0 or a 1. This results in the first hextet being a 2 (0010) or a 3 (0011). The remaining 24 bits in the hectect can be a 0 or a 1.

0010 0000 0000 0000 = 2000
0011 1111 1111 1111 = 3FFF

Hope this clears things up .

RynoR

Switch1, thats how i understand it aswell.

mikeybinec

Then you have FE80::/10 Ugh--this IPv6 addressing stuff

Switch1

mikeybinec wrote: »

Then you have FE80::/10 Ugh--this IPv6 addressing stuff

Honestly I think it's 10x easier to use over IPv4! Subnetting math is almost obsolete since most companies will just use a /64 for every subnet.

mikeybinec

I dont know about it being easier. I was practicing with my super cool new 2620XMs last night and I applied an IPv6 address but used the EUI-64 rule in applying an address. Now if you are on the remote end, you don't know what the remotes address is 'cuz it's a mix of the bia and FFFE. It's kinda random whereas a static entry in the same subnet is easier to remember.

Your explanation did help, though.. thanks