topic Re: DNS problem ??? in Operating System - Linux

DNS problem ???

Daniel Ubeda — Mon, 28 Apr 2003 20:28:38 GMT

Hi,

I want to send mails using sendmail.
I configure the sendmail.cf as relay.
.
.
DSmail_server
.
.

The linux is in a dmz zone(net 192.168.114.56), in this dmz I have a mail server 192.168.114.206(exchange).
I have defined in /etc/hosts an entry
192.168.114.206 mail_server

I want to resolv names by /etc/hosts, then I configure /etc/nsswitch.conf to resolv by files.

My problem is that when I send a mail, the mail say :
Deferred : Name Server : mail_server hosts name lookup failure

HELP please ...

Re: DNS problem ???

Jean-Pierre Denis — Mon, 28 Apr 2003 22:18:55 GMT

Hi,

you could try:

DS192.168.114.206 instead of DSmail_server.

Why resolving the name when you could send directly.

Thanks,
JP

Re: DNS problem ???

Balaji N — Tue, 29 Apr 2003 01:17:57 GMT

hi,
try this.

DS[xxx.xxx.xxx.xx]

where xxx.xxx.xxx.xxx is the ip address. in this way, it will not try to resolve the ip.

hth
-balaji

Re: DNS problem ???

Daniel Ubeda — Tue, 29 Apr 2003 11:15:46 GMT

Hi again,
I put the ip address in sendmail.cf but the message is the same ....Name Server: 192.168... host name lookup failure

any other idea ???

Re: DNS problem ???

Balaji N — Tue, 29 Apr 2003 11:32:31 GMT

hi
did u put the ip address within two square braces. (domain literal format)

if not, i guess need to setup service switch.

http://www.sendmail.org/~ca/email/doc8.12/op-sh-2.html#sh-2.5

hth
-balaji

Re: DNS problem ???

Daniel Ubeda — Tue, 29 Apr 2003 14:07:38 GMT

This is to complicated ....
I configure the file nsswitch.conf that use only files, but the error message persist.
the resolv.conf file should content any parameter ??

In HPUX I have a server in the same net, and without dns, and it resolve with /etc/hosts file !!! but this linux not work in the same way ...

Re: DNS problem ???

Daniel Ubeda — Tue, 29 Apr 2003 14:29:40 GMT

OOOO

sorry, I put the ip address into braquets and work !!!

but why don't resolve names with hosts file ????

Re: DNS problem ???

Steven E. Protter — Wed, 30 Apr 2003 01:45:09 GMT

Much better to use the IP address.

Test the DNS though.

dig

If it doesn't resolve you have networking/dns issues.

SEP

Re: DNS problem ???

Balaji N — Wed, 30 Apr 2003 01:58:04 GMT

cool. now that it works, how abt assigning points.

actually sendmail doesnt use the host file but the MX records. if you dont want to use it has to be configured in the service.switch file. also there is a config entry not to use these MX records (but dont remember now)

hth
-balaji