On 02/08/2013 09:35 AM, Gary Gendel wrote:
> On 02/08/2013 11:10 AM, Eric Shubert wrote:
>> I've received a malicious spam from the following address:
>> Received: from unknown (HELO 74-142-212-17.dhcp.insightbb.com)
>> (74.142.212.17)
>>
>> I'm a little surprised that the address hasn't been blacklisted, being
>> an apparent dynamic address. I'm using
>> dns-blacklist-entry=zen.spamhaus.org
>> dns-blacklist-entry=bl.spamcop.net
>>
>> Is there a good way to block public hosts with dhcp in their name?
>> Is there a better approach to this?
>>
> It doesn't seem to be on any of the blacklists reported by:
>
> http://multirbl.valli.org/lookup/74-142-212-17.dhcp.insightbb.com.html
>
> I see two possibilities:
>
> 1) Add dhcp as an entry in ip-in-rdns-keyword-blacklist-xxxx
> 2) add .dhcp.insightbb.com in rdns-blacklist-xxxx
>
> (1) may block legitimate addresses from anywhere just because they have
> dhcp in their rdns name.
> (2) may block legitimate addresses if any exist within that domain.
>
> Gary
>

Thanks Gary.

After reading the documentation, I've decided to put
dhcp
dynamic
in my blacklist_keywords file. I haven't used this feature in the past, 
but upon careful reading, I see that this only blocks when the keyword 
is present in the rDNS name *and* there is also a match to THE IP 
address (not just any ol' IP address) in the rDNS name. So (1) is not a 
concern after all.

Great feature, Sam. Thanks!

-- 
-Eric 'shubes'

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