Email and DNS

Steve James · External Since: Jun 25, 2009 Posts: 2

Hi,

I've got a Dual WAN router, with 2 fix IP addresses (A) and (B)
I've got a domain name : foo.com
I am running my email server.
My email server is : toto.foo.com

On my domain name configuration, I have setup :

foo.com -> my WAN fix IP address (A)
and

MX1 : toto.foo.com 10 ( toto.foo.com -> A IP address )

Now, I wish to have a email backup, using the second WAN (B)
I declare : MX2 : toto2.foo.com 20 ( toto2.foo.com -> B IP address )

So, if one of the WAN is out, the email will use the second IP address...

BUT My question is this one. My email server is the same in both case and
it's name is toto.foo.com

What will happen if the the email going through toto2 will reach the
server ?? ( the name of my server is still toto !! )

- How can I solve this probleme ??

Thanks

"C. · External Since: Jan 28, 2009 Posts: 5

On Jun 25, 10:45 am, Steve James <steve.ja....RemoveThis@never.com> wrote:
> Hi,
>
> I've got a Dual WAN router, with 2 fix IP addresses (A) and (B)
> I've got a domain name : foo.com
> I am running my email server.
> My email server is : toto.foo.com
>
> On my domain name configuration, I have setup :
>
> foo.com -> my WAN fix IP address (A)
> and
>
> MX1 : toto.foo.com 10 ( toto.foo.com -> A IP address )
>
> Now, I wish to have a email backup, using the second WAN (B)
> I declare : MX2 : toto2.foo.com 20 ( toto2.foo.com -> B IP address )
>
> So, if one of the WAN is out, the email will use the second IP address...
>
> BUT My question is this one. My email server is the same in both case and
> it's name is toto.foo.com
>
> What will happen if the the email going through toto2 will reach the
> server ?? ( the name of my server is still toto !! )
>
> - How can I solve this probleme ??
>
> Thanks

First I would suggest you establish whether it is a problem. Unplug
WAN A and try firing an email via WAN B.

If there is a problem, crank up the error logging and ask again
detailling the errors reported and **what MTA you are using** (for
sendmail, you should first try adding an entry in /etc/mail/local-host-
names for toto2.foo.com)

C.

Steve James · External Since: Jun 25, 2009 Posts: 2

Le Thu, 25 Jun 2009 06:31:52 -0700, C. (http://symcbean.blogspot.com/) a
écrit :

> On Jun 25, 10:45 am, Steve James <steve.ja... RemoveThis @never.com> wrote:
>> Hi,
>>
>> I've got a Dual WAN router, with 2 fix IP addresses (A) and (B) I've
>> got a domain name : foo.com
>> I am running my email server.
>> My email server is : toto.foo.com
>>
>> On my domain name configuration, I have setup :
>>
>> foo.com -> my WAN fix IP address (A)
>> and
>>
>> MX1 : toto.foo.com 10 ( toto.foo.com -> A IP address )
>>
>> Now, I wish to have a email backup, using the second WAN (B) I declare
>> : MX2 : toto2.foo.com 20 ( toto2.foo.com -> B IP address )
>>
>> So, if one of the WAN is out, the email will use the second IP
>> address...
>>
>> BUT My question is this one. My email server is the same in both case
>> and it's name is toto.foo.com
>>
>> What will happen if the the email going through toto2 will reach the
>> server ?? ( the name of my server is still toto !! )
>>
>> - How can I solve this probleme ??
>>
>> Thanks
>
> First I would suggest you establish whether it is a problem. Unplug WAN
> A and try firing an email via WAN B.
>
> If there is a problem, crank up the error logging and ask again
> detailling the errors reported and **what MTA you are using** (for
> sendmail, you should first try adding an entry in /etc/mail/local-host-
> names for toto2.foo.com)
>
> C.

Oh yes... sorry I forgot to mention my MTA : Sendmail

Really ????? I should add toto2.foo.com into /etc/mail/local-host-
names ??

I thought, that it was only for domain name that sendmail will accept ? :
foo.com and toto2.foo.com is the name of my local machine ?!

If I remember correctly, this toto2.foo.com is into network configuration
file ?!

Did I misunderstand everything ?