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On Thu, Jul 30, 2020 at 10:05:46AM +0100, antlists wrote in |
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<b11e9eef-08e5-7e2a-ff35-2a118dbb8328@××××××××××××.uk>: |
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>From what little I understand, IPv6 *enforces* CIDR. So, of the 64 |
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>network bits, maybe the first 16 bits are allocated to each high level |
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>allocator eg RIPE, ARIN etc. An ISP will then be allocated the next 16 |
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>bits, giving them a 32-bit address space to allocate to their |
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>customers - each ISP will have an address space the size of IPv4?! |
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> |
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>Each customer is then given one of these 64-bit address spaces for |
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>their local network. So routing tables suddenly become extremely |
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>simple - eactly the way IPv4 was intended to be. |
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An IPv6 address is 128 bits in length. Usually an ISP allocates 64 |
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bits to a single customer, allowing the systems on/behind that |
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connection to automatically assign themselves an address based on |
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their MAC address for example. Note that also allocations bigger than |
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64 bits are common so customers get 70 or 76 bits to use and can use |
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multiple subnets on their home/business networks. |
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Point is though, with IPv6 addresses are no longer a scarce |
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commodity. The cost to an ISP to give you one IPv6 address (/128) is |
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just the same as given you enough room for your own IPv4 internet |
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(/64). Whether they make them static or dynamic depends on their |
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policy and what their customers are willing to put up with / pay for. |
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