[erlang-questions] Use of http:request

Greg Smyth <>
Fri Jan 15 12:06:12 CET 2010


On Thu, Jan 14, 2010 at 10:52 PM, Tomas Abrahamsson
<> wrote:
>> I'm having a bit of a problem understanding why http:request is
>> returning "{error,nxdomain}" - whenever the box seems to resolve
>> properly via inet:gethostbyname:-
>
> What version of Erlang are you running?

I have access to 2 machines, one running R12B-5 (inets-5.0.12), and
one running R13B-1 (inets-5.0.13) - both are currently exhibiting the
same failure with http:request....

>
> This has happened to me with R12B-5 (inets-5.0.12), I think, but I cannot
> reproduce it with the R13B02 (inets-5.1.3) I currently have at hand.
>
> The problem in my case was that the web server had both an ipv6
> address and an ipv4 address, and I didn't have any ipv6 networking
> properly set up, and the http:request in R12B-5 by default tried first ipv6
> then ipv4. So it found an ipv6 address, couldn't reach it and ended up
> with an {error,enetunreach}.
>
> You could try to run "dig AAAA webserver001.cluster1.company.com"
> or inet:gethostbyname("webserver001.cluster1.company.com", inet6).
> to see if it has an ipv6 address. In my case it was the www.ida.liu.se
> that I tried to reach.

This is where it gets interesting... :)

I get an ipv6 address for the webserver returned from
inet:gethostbyname in R13 - but not in R12 (and interestingly, not
from a "dig AAAA" on either machine)

>
> If this is the problem for you, then you may try
> http:set_options([{ipv6,disabled}]).

Tried this on both machines - doesn't seem to make a difference for
this particular case...

Thanks for the help,
Greg

>
> BRs
> Tomas
>


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