[Dnsmasq-discuss] [PATCH] DHCPv6 - List or Range reservation for single host

Simon Kelley simon at thekelleys.org.uk
Sun Jan 26 18:27:34 GMT 2020

On 21/01/2020 22:38, Tore Anderson wrote:
> * Simon Kelley
>> I have an alternative suggestion for the syntax of dhcp-host.
>> It's less flexible, but simpler and easier to understand and to explain,
>> and uses existing semantics rather than adding new keywords.
>> The idea is just to add a prefix-length to the address. That allows you
>> to define (eg) 1,2,4,8, or 16 addresses for use by a host simply and
>> easily in a way which makes it difficult to accidentally overlap address
>> ranges, and is fairly obvious to anyone who has done done any IPv6
>> network configuration.
>> for instance to reserve four addresses for each host we cold do:
>> dhcp-host=00:11:22:33:44:55,[fd12:3456::aa00/62]
>> dhcp-host=00:11:22:33:44:56,[fd12:3456::aa04/62]
>> dhcp-host=00:11:22:33:44:57,[fd12:3456::aa08/62]
>> As a sanity check, if the "host part" of the address isn't zero,
>> ie [fd12:3456::aa01/62]
>> that could be rejected with an error.
> I have done quite a bit of IPv6 networking, but the use of /62 here is anything but «fairly obvious» to me.
> It would have been much more intuitive to use /126, in my opinion.
> Tore

/62 was a late-night-long-day brain fade. Of Course, I meant /126 :)


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