Multiple PTR records

[Matus UHLAR - fantomas]

> On Jan 15, 2009, at 6:33 AM, Halassy Zoltán wrote:
> >I don't want to break forward <-> reverse mapping.
> >
> >www.example.com. A 1.2.3.4
> >mail.example.com. A 1.2.3.4

> >4.3.2.1.in-addr.arpa. PTR www.example.com.
> >4.3.2.1.in-addr.arpa. PTR mail.example.com.

> >Would this one break anything? Or anyone else have a better tip how  
> >could i handle this situation? Multiple PTRs in this case is really  
> >an issue?
> 
On 15.01.09 10:19, Chris Buxton wrote:
> Yes, it is an issue. Remove this record:
> 
> 4.3.2.1.in-addr.arpa. PTR www.example.com.
> 
> Your web server doesn't need a PTR record.

> >The main thing i don't want to break forward <-> reverse symmetry  
> >cause there are some sanity checks about this (like in spamfiltering).
> 
> Right, your mail server ought to have a PTR record. Your web server,  
> however, does not need it.

Actually, it doesn't matter which PTR record will remain, unless there will
be any SPF record pointing to it. 
And even a mail server does not need PTR record, if it only accepts mail,
but does not send. 

The valid PTR is important when sending mail - many servers will refuse
connections from IP's without valid PTR and A records.

The contents of the record is not that much important (unless using SPF),
although some servers refuse mail from generic-looking names
(e.g. a-b-c-d.anything.example)


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