IPv6 subnetting

all right so I'm going to walk you through ipv6 subnetting but first before we get started I want to show you the parts of an ipv6 address now remember it's 128 bits total but it's broken up into three sections the first 48 bits is the global routing prefix the next 16 bits is your subnet ID and the last 64 bits is your interface identifier so let's look at an example of an ipv6 address 2 0 0 1 2 a 1 C ad 0 slash 64 so I wrote it up this way so that you would see that these first 48 bits remember it's written in hexadecimal so each digit represents four bits or a nibble so that's four eight twelve sixteen sixteen bits in each part so 16 plus 16 is 32 plus 16 is 48 so this is your 48 bit prefix and then I wrote this out into all zeros so you could just see how the subnet portion is represented so this whole portion together is slash 64 so let's break up this subnet portion and look at it in binary rather than in hexadecimal so I'm binary each one of these digits represents four bits that would be one two three four five six seven eight nine 10 11 12 13 14 15 16 so that's each digit okay so how do we subnet ipv6 you just basically start counting in this last nibble and work your way up all right so let's do that turn that one on two three four and just keep going all right so that would be represented in the last octet by zero zero zero one zero zero zero C sorry zero zero zero zero there 0 1 0 0 and 0 2 0 0 0 3 0 0 0 4 and so forth it would actually be written since you get rid of your leading zeros as 0 1 2 3 4 and that's what would be represented here in this subnet subnetwork portion you would count all the way up to F for that last number right there F and then as you keep going as that becomes F then you would start in this third section until that becomes F then going to start here F once you're completely filled up would be F F all right so let's look at a problem all right so here's the problem your ISP has given you the ipv6 address to 0 0 0 AC a D 1 2 3 4 6 6 0 0 with a subnet mask of 56/58 so what's that what that is telling us is all right we have our 48 bits here but let's look at this in binary 66 and binary would be 0 1 1 0 0 1 1 0 0 0 0 0 0 0 0 so that's our subnet ID in binary so we have 48 bits 49 50 51 52 53 54 55 56 that gives us our / 56 so we still have these 8 bits to look at I'm in order to subnet so there's still 8 bits available so our first question is how many subnet bits are available well there's eight that haven't been used so two to the eighth is 256 so 256 different subnet work so you can create out of this alright so what are our first six well actually let's do first four so I'll just write so many so our first four subnets would be six six I'm just going to write that out since we've already seen it in binary 1 2 3 4 5 6 7 8 6 6 1 2 3 4 5 6 7 8 1 2 3 4 5 6 8 let's see one more 2 3 4 5 6 all right so our first four sub-networks would be six six zero zero six six zero one six six zero two sorry and six six zero three those would all be a slash 64 now let's look at our last skip all the way down to our last two subnets remember the very highest value in hexadecimal is F so that would be six six let's turn these all along and these will just leave the last one off six six eight okay so that would actually equal six six f e and six six F F slash 64 for both of this those would be your last subnets available so as you can see whenever your subnetting with ipv6 you basically just have to look at your sub network portion in binary and you work your way all the way from right to left as you turn on your bits so in the last digit you're going to look at those last four bits and just start counting remember you're always working with nibbles because it's hexadecimal value so it's one two four eight one two four eight one two four eight one two four eight for that entire portion of your subnet whenever you have a value that's not 48 then you know that you've already used some of your sub network bits so you don't have the full 16 to look at so always look at in binary you can see that we have a slash 56 so there's only actually eight bits left to subnet or 256 possible sub networks so whenever you look at it that way you have your 0 1 2 3 4 5 6 7 8 9 ABCDE F is the value in this last digit and the same thing for that next digit all right so they're subnetting in ipv6

Channel: ADharamsi

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Id: YFkO_axsrks

Length: 8min 13sec (493 seconds)

Published: Tue Oct 07 2014