spf-discuss
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Re: How to define SPF for a domain with 115 distinct IP Addresses

2004-09-27 08:25:29
On Mon, 27 Sep 2004, Devendra Singh wrote:

We have around 115 IP Address for our different Servers. A few of the IP
Addresses are in consecutive ranges but mostly are from separate pool.

When I try to define the TXT Record for TinyDNS they do not fit into the
field (perhaps the limit is of 255 characters).

We do send emails from our MUAs using only about 7-10 Server IP-Addresses. 
But, we have many Servers which hosts websites as virtual hosting on around 
100 different IP addresses (pool is different). These websites send queries 
to the respective client addresses. For the purpose of "Envelope Sender" we 
need to define SPF. We do not wish to use INCLUDE to include the SPF of the 
hosting data center, which would include a very vast range of IP Addresses.

You could define your own subdomains to include.  E.g.:

example.com IN TXT "v=spf1 include:dc1.example.com include:dc2.example.com -all"
dc1.example.com IN TXT "v=spf1 ip4:1.2.3.4 ip4:1.2.4.5 ip4:1.3.4.5"
dc2.example.com IN TXT "v=spf1 ip4:2.3.4.5 ip4:2.3.5.6 ip4:2.4.5.6"

-- 
              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.