[Dnsmasq-discuss] autogenerating dns records

Simon Kelley simon at thekelleys.org.uk
Thu Apr 25 11:17:42 BST 2013

On 25/04/13 10:17, Vladislav Grishenko wrote:
> Hi Simon,
> Really, good feature, thanks for including it.
> Have a suggestion not for naming, but for ipv6 reverse domain algo. Since
> ipv6 domain representation could be quite long, it can be shortened.
> For example, using duotrigesimal system (base 32) + zero compression:
> 2001:db8::1 =>  1zigr64z21
> 2001:db8:1234:5678:90ab:cdef:1234:5678 =>  ojl839stdua19spakh4gr64z21

I'm not clear what the advantage is. The maximum length of the 
presentation form of an IPv6 address is 46 characters, which fits in a 
DNS label (63 max) quite comfortably. By encoding the address, that 
makes it useless for humans, which is the main point of doing this, plus 
you'd have to support the encoded form in forward as well as reverse 
queries, since people will do a reverse query and then use the result in 
a forward query later.

You've reminded me however that the prefix is limited to 63-46 for IPv6, 
to be sure to avoid the label length limit.



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