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Re: Slow connection time - turning off reverse DNS lookup

Felipe Rechia feliperechia@gmail.com
Fri, 21 Oct 2011 20:35:41 GMT

> What do you get if you do nslookup on the different host names? Do you see delays there too?

since the lookup time that I am wasting is in my conserver-server,
here is the output that I get with nslookup and host commands:

felipe.rechia@lombardi:~$ nslookup

** server can't find NXDOMAIN

felipe.rechia@lombardi:~$ host
Host not found: 3(NXDOMAIN)

> The reason I ask is that if you indeed have a DNS server responding your replies should be instant.

The replies are indeed immediate. The DNS server simply replies that a
name is not known. The problem is that my conserver-servers keep
trying again to lookup a hostname for my client address, as I've
verified by using wireshark to capture DNS traffic... :(

>Suppose the DNS server itself has some problems left over from your IP migration. I perused the code briefly and I see nothing that leads me to believe conserver is deliberately trying to look up IP addresses in reverse, other than the regular gethost* functions.

Well, Chris Fowler has made this statement at the beginning of the
discussion, which makes me think that there is indeed reverse dns
lookup going on:
>>In 7.2.X I had this problem and simply commented out the revers look up.
>>In my use I have no need to know the name that is associated with and

I didn't want to have the trouble to update the code and generate new
binaries just to turn off DNS... :(. Maybe that is my only option now.
I was looking for a more user-friendly solution, because I have 6
servers and 10 clients to update now...

> Look at your DNS configuration first. Seems something is broken there.

It is certainly broken, I don't have name resolution for this ip
address range! But I don't want to have!
I will take a better look at the DNS issue, maybe I could solve it by
using a different approach as suggested by Dirk in another e-mail!

Thanks again for your input :)