issue with reverse resolving

Paul Slootman paul+rsync at
Mon Dec 24 12:04:56 GMT 2007

Apparently the reverse resolving is always done, when a client connects
to an rsync daemon; this can be a problem with anonymous rsync access
where the whole world may connect but a large part of the world doesn't
have its reverse resolving working.  In these cases you have to wait for
the DNS lookups to time out before the transfer proceeds.

As far as I can see, this is done in case there's a hostname restriction
in a "hosts allow = " line; and the name found is used in logging.

However, if there's no name used in restricting access (or perhaps even
no restrictions at all), the reverse resolving can get in the way.
There's a reason why e.g. apache configs usually don't log the hostname
of clients connecting, just the IP address...

Ideally the reverse lookup would be delayed until deemed necessary by
use of a name (or wildcard name) in a "hosts allow" line. For those who
care about having a name in the logfile a new switch could be added?

I'm sure older versions didn't do the reverse lookup by default, BTW.

Paul Slootman

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