spf-discuss
[Top] [All Lists]

Re: [spf-discuss] Question on a unified policy record approach

2005-09-06 08:43:36
On Tue, 6 Sep 2005, Commerco WebMaster wrote:

I'm probably missing something here.  If so, sorry to be obtuse and 
please clue me in.

A host with multiple IP addresses and multiple names
is no problem for DNS or for EHLO checking.  DNS supports multiple
A records for a name and multiple PTR records for an ip.

For example:

;EHLO name:
jupiter.example.com     IN A 10.0.0.1
jupiter.example.com     IN A 10.1.0.1
jupiter.example.com     IN A 10.2.0.1

;interface names
jupiter0.example.com    IN A 10.0.0.1
jupiter1.example.com    IN A 10.1.0.1
jupiter2.example.com    IN A 10.2.0.1

And EHLO would be jupiter.example.com.

Although checking EHLO doesn't use them, you can also make PTR return
multiple names for an IP:

$ORIGIN 10.in-addr.arpa.
1.0.0   IN PTR jupiter.example.com.
1.0.0   IN PTR jupiter0.example.com.
1.0.1   IN PTR jupiter.example.com.
1.0.1   IN PTR jupiter1.example.com.
1.0.2   IN PTR jupiter.example.com.
1.0.2   IN PTR jupiter2.example.com.

The only "problem" is that the poster doesn't feel that mail servers
should be required to have consistent DNS records.

-- 
              Stuart D. Gathman <stuart(_at_)bmsi(_dot_)com>
    Business Management Systems Inc.  Phone: 703 591-0911 Fax: 703 591-6154
"Confutatis maledictis, flamis acribus addictis" - background song for
a Microsoft sponsored "Where do you want to go from here?" commercial.

-------
Sender Policy Framework: http://spf.pobox.com/
Archives at http://archives.listbox.com/spf-discuss/current/
To unsubscribe, change your address, or temporarily deactivate your 
subscription, 
please go to 
http://v2.listbox.com/member/?listname=spf-discuss(_at_)v2(_dot_)listbox(_dot_)com

<Prev in Thread] Current Thread [Next in Thread>