On 2/26/2014 10:35 AM, Matteo Cazzador wrote:
Hi, i've configured my postifx to manage different location (server)
with the same domain.
I've configured 4 postfix mx record one for every site (location/server).
My configuration is like this:
example.com in virtual_alias_domains
$myhostname in mydestination or virtual_mailbox_domains
/etc/postfix/virtual:
w...@example.com w...@mail.site1.example.com
d...@example.com d...@mail.site1.example.com
q...@example.com q...@mail.site3.example.com
r...@example.com r...@mail.site2.example.com
etc....
Dig interrogation:
example.com. 21599 IN MX 30 mail.site1.example.com.
example.com. 21599 IN MX 40 mail.site2.example.com.
example.com. 21599 IN MX 50 mail.site3.example.com.
example.com. 21599 IN MX 10 mail.example.com.
Every mail server knows the user of every site and redirect eventually
mail to right site.
I've a problem.
ADSL of mail.site1.example.com going down, i've a backup adsl on site 1
(with different external IP obviusly), how i can
manage two adls ip for the same mail.site1.example.com ? is it possible?
Yes, you can set up more than one A record for mail.site1.example.com.
However, since DNS is fundamentally random in nature, this does not
guarantee that the backup link is used as such; on average, both will be
used equally.
Can i define one other MX record to prevent adsl break?
How? is it possible di define
example.com. 60 mail.site1.example.com that point to another
external adsl ip address?
This too is possible, but again, will probably not have the effect you
are after.
Backup (=lower-priority) MX records tend to act as spam magnets, thus
actually /increasing/ the traffic to those hosts.
It hasn't been advisable to use backup MXes for a long time now.
Can i act using only dns without manage postfix configuration?
Not trivially; something like an actual IP load balancer would be best
for that, as it can weigh the IPs differently.
Of course, this also does not apply in the case of separate public IPs.
--
J.
