Reverse DNS lookups on accept in network

Yitzchak Gale gale at
Wed Apr 10 00:59:53 CEST 2013

I wrote:
>> As for the Hackage problem, this problem is inherent to CGI, which is
>> what Hackage currently uses. The CGI protocol supplies the resolved
>> client host name to the web application in an environment variable.

Anders Kaseorg wrote:
> This is not required by the CGI protocol.  Apache only provides REMOTE_HOST
> if the HostnameLookups directive is set to On (the default is Off).  So this
> should be easily fixable.

Interesting, thanks. But it really does seem that
Hackage is doing an RDNS lookup for every connection
to a CGI app, both Haskell and non-Haskell. I don't
have direct access to the server, but the sysadmin
says that Apache is configured not to do lookups.
And HostnameLookups did come up in the conversation.
I'll ask again specifically about HostnameLookups.
Can you think of any other reason that every CGI
connection would trigger an RDNS lookup of the
remote host?


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