[CLUE-Tech] reverse DNS

[Charles Oriez]

At 12:38 PM 9/10/2004, Angelo Bertolli wrote:

>Even if there is no RDNS, can't you still block based on IP address?  I 
>mean is it now a requirement to have RDNS set up?

recommended procedure is to do both.  First step is to refuse connections 
for invalid RDNS. Second step is to check access.db for local lists of 
black- or white-listed addresses (for instance, I dont bother checking the 
blacklists for comcast's SMTP servers, yahoo, aol, etc since virtually no 
spam comes that way), then check the dnsbls for listed IPA's.

since there is really no technical justification for not having valid rdns 
on any valid server, requiring rdns to be valid on incoming servers is a 
simple method to block the many trojaned machines




--

Charles Oriez     coriez at oriez.org    39  34' 34.4"N / 105 00' 06.3"W
**
"Drag God into politics, and you'll ruin his reputation in no time." -
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