ML a écrit :
Hi Wietse,
I have some confusion about multiple reverse PTR records per IP.
You need only one.
The name (from the address->name) lookup must resolve to the address.
I am still confused.
Like my example below, what happens if I want to setup a single mail server
that hosts mail for 20 different domains? I am told that 18 of those domains
will be blacklisted and SMTP will fail because the lookup wont grab the right
record.....
for a given IP, you only setup one PTR.
do not confuse this with "multihoming", where you assign multiple IPs to
a single name (that is, you use multiple A for a single name).
in short you only need somthing like this:
192.0.2.1 => sillywilly.example.com
sillywilly.example.com => 192.0.2.1
mail1.example.com => 192.0.2.1
mail2.example.com => 192.0.2.1
mail3.example.com => 192.0.2.1
...
as you see in this example, the IP resolves to a single name (PTR), but
many names resolve to that IP.
finally, the IP and hostname of the box have nothing to do with the
domains you host mail for. Think about Postini, google, ...
