Re: [NTISP] Spam Filtering
Sat, 06 Mar 1999 23:13:02 -0600

Had to comment on this...

most upstreams will delegate out the authority for inverse on IPs they
assign out to their customers...

However, setting up reverse lookup on IPs is not a requirement so
blocking access due to not having it is really the fault of the person
doing the blocking (it is also their choice though). We do forward
and reverse and reverse is more IP accounting then anything...but, not
having it isn't a very good reason to block access to anything. Is
there an RFC out there that states it has to be done...of course I
doubt many of those ISPs even know what an RFC is.

We took one step too far in blocking SPAM recently and implemented
ORBS...I was totally SHOCKED by the amount of mail being blocked
because remote mail servers had open relay. I can see where sometimes
you would want open relay, however, THAT is the major cause of
spam...not the absence of reverse lookup on an IP. If only 10% of the
clueless admins would buckle down their mail servers and not allow
mail relay I bet it would cut 50% of the SPAM. Needless to say we had
to remove blocking mail servers that had open relay...too much mail
was being rejected.

Just my .02

On Sat, 6 Mar 1999 17:00:20 -0600, you wrote:

>>Sorry, just had to comment on your statement about reverse lookup. =
>> is the authority for IP numbers, they allocate them to the ISP=
>>purchases them and the responsibility for reverse lookup falls to that =
>>Since most smaller ISPs have about two or three jumps to the owner of =
>>subnet, they usually don't ever get the responsibilty for the reverse
>>so the reverse lookup method of filtering mail is absurd if not insane.
>Sorry, I will disagree with you. You ought to have your upstream make =
>the authority for the network you are controlling. That is a simple =
>for them and then you can do this inverse addressing for yourself. We =
are a
>small ISP and in the same situation but you have every right to be the
>authority over your own network and your upstream can help you and most
>often is willing to if you ask. Especially if you explain WHY.
>David Payer
>OMNI Internet
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