Am 08.11.2011 18:23, schrieb Jonathan Vomacka:
> Good afternoon Gentlemen,
>
> I have a question regarding /etc/hosts for CentOS 6 x64. I already have
> a hostname set on my server, however there are 10 additional IP aliases
> assigned to the box, one which I plan to use as a mail server. The mail
> server will be serving mail for a completely different domain (different
> then the default hostname of my box). My question is this: If I take one
> of my additional IP addresses and bind it to postfix for mail, do I also
> have to specify the remote IP and mail server hostname in /etc/hosts?
>
> For example my hosts looks something like this
> 127.0.0.1 localhost
>
> Can I add?
> 66.x.x.x mail.foo.bar
>
> Is this even necessary?

not if your dns-servers on LAN and WAN are configured right and
if this is not the case you must not run a public mailserver

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Reindl,

To my knowledge, all that needs to be configured is A records, MX
records, and SPF records (along with correlating PTR's). This is a whole
other subject and I feel I will have this correctly configured. My fear
is that someone will send email out from my server, and the hostname
might come back as my systems host INSTEAD of the mail server hostname.

Is it good measure to add it to the hosts file anyway or is this a waste
of time? I guess my understanding of the host file is clouded.

On 11/8/2011 12:50 PM, Reindl Harald wrote:
> Am 08.11.2011 18:23, schrieb Jonathan Vomacka:
>> Good afternoon Gentlemen,
>>
>> I have a question regarding /etc/hosts for CentOS 6 x64. I already have
>> a hostname set on my server, however there are 10 additional IP aliases
>> assigned to the box, one which I plan to use as a mail server. The mail
>> server will be serving mail for a completely different domain (different
>> then the default hostname of my box). My question is this: If I take one
>> of my additional IP addresses and bind it to postfix for mail, do I also
>> have to specify the remote IP and mail server hostname in /etc/hosts?
>>
>> For example my hosts looks something like this
>> 127.0.0.1 localhost
>>
>> Can I add?
>> 66.x.x.x mail.foo.bar
>>
>> Is this even necessary?
>
> not if your dns-servers on LAN and WAN are configured right and
> if this is not the case you must not run a public mailserver
>
>
>
>
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> Is it good measure to add it to the hosts file anyway or is this a waste
> of time? I guess my understanding of the host file is clouded.
>

Yes, waste of time. It's all in how you've configured postfix to handle
it. The default is to the FQDN of the server, but I'd suggest you change
accordingly (ie: myhostname).
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Am 08.11.2011 18:53, schrieb Jonathan Vomacka:
> Reindl,
>
> To my knowledge, all that needs to be configured is A records, MX
> records, and SPF records (along with correlating PTR's). This is a whole
> other subject and I feel I will have this correctly configured. My fear
> is that someone will send email out from my server, and the hostname
> might come back as my systems host INSTEAD of the mail server hostname.
>
> Is it good measure to add it to the hosts file anyway or is this a waste
> of time? I guess my understanding of the host file is clouded

the host-file is simply the same as DNS in both directions and
does nothing than resolve name/ip locally, normally not needed
but maybe a good idea to make sure servers like httpd starts
even if no dns is reachable at this moment because httpd refuses
to start if he can not resolve his own name


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Okay so the host file only allows system applications to understand what
IP's are bound to a specific host, but in actuality, DNS has to be setup
correctly in terms of a public server.

Is my understanding is correct now, then I think I am good to go.
Thanks for all your help who responded to this thread Gentlemen.

On 11/8/2011 1:06 PM, Reindl Harald wrote:
>
>
> Am 08.11.2011 18:53, schrieb Jonathan Vomacka:
>> Reindl,
>>
>> To my knowledge, all that needs to be configured is A records, MX
>> records, and SPF records (along with correlating PTR's). This is a whole
>> other subject and I feel I will have this correctly configured. My fear
>> is that someone will send email out from my server, and the hostname
>> might come back as my systems host INSTEAD of the mail server hostname.
>>
>> Is it good measure to add it to the hosts file anyway or is this a waste
>> of time? I guess my understanding of the host file is clouded
>
> the host-file is simply the same as DNS in both directions and
> does nothing than resolve name/ip locally, normally not needed
> but maybe a good idea to make sure servers like httpd starts
> even if no dns is reachable at this moment because httpd refuses
> to start if he can not resolve his own name
>
>
>
>
>
> _______________________________________________
> CentOS mailing list
> CentOS@centos.org
> http://lists.centos.org/mailman/listinfo/centos
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Reindl Harald wrote:

Am 08.11.2011 18:53, schrieb Jonathan Vomacka:


Reindl,

To my knowledge, all that needs to be configured is A records, MX
records, and SPF records (along with correlating PTR's). This is a whole
other subject and I feel I will have this correctly configured. My fear
is that someone will send email out from my server, and the hostname
might come back as my systems host INSTEAD of the mail server hostname.


Is it good measure to add it to the hosts file anyway or is this a waste
of time? I guess my understanding of the host file is clouded



the host-file is simply the same as DNS in both directions and
does nothing than resolve name/ip locally, normally not needed
but maybe a good idea to make sure servers like httpd starts
even if no dns is reachable at this moment because httpd refuses
to start if he can not resolve his own name



also refer to /etc/resolv.conf
this file tells the system where to go for hostname lookups - as
mentioned, if dns is unavailable during boot some things can get lost.

------------------------------------------------------------------------


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Jonathan Vomacka wrote:
<snip>
> Is my understanding is correct now, then I think I am good to go.
> Thanks for all your help who responded to this thread Gentlemen.
<snip>
*sigh*
There are women on this list, also - Margaret Doll comes to mind, though
many folks of both sexes are lurkers, so addressing the list as
"Gentlemen" is inappropriate.

mark "gentleman? No, neither by breeding nor act of Congress"


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