[ntp:questions] Pool returns IPv6 address to IPv4 query

Brian Utterback brian.utterback at oracle.com
Wed Nov 20 03:48:56 UTC 2013

On 11/19/2013 3:40 PM, Danny Mayer wrote:
> You should not be using literal IP addresses of either flavor without
> also setting the AI_NUMERICHOST flag otherwise it tries to do a DNS
> lookup. That's poorly written code otherwise.
> Danny

Not so. The getaddrinfo function will recognize literal addresses and 
merely convert them. The point is that for something like ssh or any 
other network utility, the user is supposed to give a hostname, but in 
virtually all cases you can give a literal address and the application 
does not have to treat it differently. If you read the ipng mailing 
list, you will see that they were trying to make the whole process of 
writing a network application simpler, with getaddrinfo doing the heavy 
lifting for all of the major cases. At the same time they were trying to 
allow applications to work on either IPv4 or IPv6 systems without 
changing them, or dual stack or any combination. But no matter what they 
did there were edge cases that needed to work differently.

Brian Utterback

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