You are viewing a plain text version of this content. The canonical link for it is here.
Posted to httpclient-users@hc.apache.org by vigna <vi...@di.unimi.it> on 2012/12/30 08:59:27 UTC

On Linux, Java issues reverse DNS lookups when a socket is opened.

I apologize in advance: technically this is not a post about
DefaultHttpClient, as the same behaviour happens using URL.openConnection(),
but we met this behaviour the first time using DefaultHttpClient, and if
anybody else had the same problem this might ring a bell.

I have posted the question in detail on stackoverflow:

http://stackoverflow.com/q/14087634/1937350

Basically, when an address is looked up using InetAddress.getAllByName() or
DNSJava's Addess.getAllByName(), everything works as expected. But when we
actually try to open a socket using Apache HTTP Component's
DefaultHttpClient (or URL.openConnection()), we find that a reverse lookup
is performed on the IP address.

I really hope someone has an explanation, because I couldn't find any :(.
The same behaviour is *not* seen on Mac OS X, for instance.



--
View this message in context: http://httpcomponents.10934.n7.nabble.com/On-Linux-Java-issues-reverse-DNS-lookups-when-a-socket-is-opened-tp18590.html
Sent from the HttpClient-User mailing list archive at Nabble.com.

---------------------------------------------------------------------
To unsubscribe, e-mail: httpclient-users-unsubscribe@hc.apache.org
For additional commands, e-mail: httpclient-users-help@hc.apache.org


Re: On Linux, Java issues reverse DNS lookups when a socket is opened.

Posted by sebb <se...@gmail.com>.
According to the latest post [1]:

"In the end, the only real problem was that I was not giving tcpdump
the -n option. The reverse lookup I was observing were just
tcpdump's."

i.e. not a problem.

[1] http://stackoverflow.com/a/14150693

On 30 December 2012 16:59, vigna <vi...@di.unimi.it> wrote:
> I correct myself: it happens on Mac OS X, too.
>
>
>
> --
> View this message in context: http://httpcomponents.10934.n7.nabble.com/On-Linux-Java-issues-reverse-DNS-lookups-when-a-socket-is-opened-tp18590p18591.html
> Sent from the HttpClient-User mailing list archive at Nabble.com.
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: httpclient-users-unsubscribe@hc.apache.org
> For additional commands, e-mail: httpclient-users-help@hc.apache.org
>

---------------------------------------------------------------------
To unsubscribe, e-mail: httpclient-users-unsubscribe@hc.apache.org
For additional commands, e-mail: httpclient-users-help@hc.apache.org


Re: On Linux, Java issues reverse DNS lookups when a socket is opened.

Posted by vigna <vi...@di.unimi.it>.
I correct myself: it happens on Mac OS X, too.



--
View this message in context: http://httpcomponents.10934.n7.nabble.com/On-Linux-Java-issues-reverse-DNS-lookups-when-a-socket-is-opened-tp18590p18591.html
Sent from the HttpClient-User mailing list archive at Nabble.com.

---------------------------------------------------------------------
To unsubscribe, e-mail: httpclient-users-unsubscribe@hc.apache.org
For additional commands, e-mail: httpclient-users-help@hc.apache.org