IPV6_RECVPKTINFO not working for IPv4-mapped addresses on Linux?

Francis Dupont Francis.Dupont at fdupont.fr
Wed Jan 22 17:54:14 CET 2014

 In your previous mail you wrote:

>  On 20/01/2014 17:12, Simon Perreault wrote:
>  > IIRC, recent versions of Bind open a socket per address on IPv4

=> not it is not by choice, just:
 - DNS requires to answer from the address the request was received
 - there is no standard/portable way to do this without the one
  socket per address in IPv4 (if you need an argument, just ask what
  this discussion is about :-)

>  this feature was one of the main reasons I stopped using BIND.  It has the
>  side effect that you cannot necessarily set it up on a system which shares
>  IP addresses using e.g. VRRP, because you cannot be guaranteed that the
>  system will have the virtual IP address configured at the time that BIND
>  starts.  Frustrating.

=> BIND polls from time to time interfaces to bind() to new addresses
(again, there is no standard/portable way to be notified. BTW we (ISC)
know this is a point which can be improved so if you know a generic
simple solution...)


Francis.Dupont at fdupont.fr (also fdupont at isc.org)

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