Samba and DNS

[Ahmed RAHAL]

Hi,

> 
> I have half of a class C assigned to my network (/25 netmask
> 255.255.255.128) and the reverse (PTR) records must be
> maintained on my ISP's side. (no one wants the 'hassle' of
> working out a scheme to delegate the in-addr-arpa. to us for
> half the block) As it stands I have only asked
> them to include the server's PTR so that I can ftp, etc. from
> sites if I need patches or whatever.
> 
> This works fine as I don't really need to advertise my various
> Winx clients to the outside world but I see this error quite a
> bit in the log.smb:
> 
> [2000/09/07 15:34:52, 1] lib/util_sock.c:client_name(852)
>   Gethostbyaddr failed for 209.91.24.193
> [2000/09/07 15:44:34, 1] lib/util_sock.c:client_name(852)
>   Gethostbyaddr failed for 209.91.24.200
> [2000/09/07 15:45:03, 1] lib/util_sock.c:client_name(852)
>   Gethostbyaddr failed for 209.91.24.193
> [2000/09/07 15:49:11, 1] lib/util_sock.c:client_name(852)
>   Gethostbyaddr failed for 209.91.24.200
> 
> Now, what I understand is that this is because the reverse lookup is
> failing (there are no PTR records for these machines at the ISP by
> choice). What I am wondering is if I am suffering any kind of
> 'performance' hit due to these lookup attempts when connections
> are made to samba shares by various machines? 

 I guess that this reverse DNS request must take some time,
and maybe slow down the connection process.
The easy way around this is to provide the Unix machine's /etc/hosts
file with the IP adresses so the lookup process (reverse Lookup in here)
should be ultraquick !
Watch out : that the normal lookup process goes
first through /etc/hosts and then through DNS,
else lookup would not fail, but take some time anyway

Resolution order can be set on any unix machine.

bye,

Ahmed RAHAL
Taranis Services S.A.