Re: Stupid DNS queries

[Chris Lowth]

theking wrote:
> Hello,
>
> I have a linux box on a local network
> This is a redhat 8
> There is no DNS server on the linux, nor on my local network, so the
> /etc/resolv.conf has the DNS servers of my ISP.
>
> My problem : this stupid box makes stupid reverse DNS queries when I
> connect to it (for example with telnet) from a machine on my network
> whitch is not known in its /etc/hosts file.
> This makes my gateway connecting uselessly to internet !
> And I don't want add all names of machines on my network in all hosts
> files.
>
> My questions :
> 1) I suppose linux wants to know the name of the machine whitch connects
> to it, to put the name in a log, am I right ?
> 2) Can I disable this name lookup ?
> 3) The most interesting : why this system makes DNS queries for machines
> which are on the local network ? I have not found in
> redhat-config-network the same option as in windows : "don't use DNS for
> local addresses"
> Note : the local network address and mask are correctly set.
>
> Thanks

Strikes me that it could be tcp_wrappers doing its stuff. This is the 
code that looks in /etc/hosts.allow and /etc/hosts.deny to find out 
whether or not to allow access.

Do you have host or domain names in your /etc/hosts.allow file? - if so, 
try replacing them with IP addresses.

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