On Tue, 2003-09-16 at 15:35, Kenneth Kabagambe wrote:
> ---------- Original Message -----------
> From: Patrick Okui <[EMAIL PROTECTED]>
> To: [EMAIL PROTECTED]
> Sent: 16 Sep 2003 13:55:28 +0300
> Subject: Re: lug_: DNS and verisign -- all .COMs now exist
> 
> > On Tue, 2003-09-16 at 13:27, Paul Bagyenda wrote:
> > > What do the ISP guys feel about this:
> > >
> > 
> > we've routed the IP to NULL0 aka /dev/null on our distribution routers.
> > if all ISPs do something similar, we won't have that much of a problem.
> > 
> > my 2 cents.
> > Patrick.
> > Patrick Okui <[EMAIL PROTECTED]>
> > Systems Administrator
> > One2Net (U) Ltd
> > 
> > ---------------------------------------------
> > This service is hosted on the Infocom network
> > http://www.infocom.co.ug
> ------- End of Original Message -------
> 
> But Patrick, wont this just cause email servers behind your routers to 
> quickly queue up with mail, with a Connection Timeout? I would think that 
> doing reverse dns lookups would be better since they would filter out those 
> domains that donot exist and maybe someone can hackup a script to 
> automatically blacklist those domains that fall in this category.

Hi Ken

Yes it will. Ideally most MTA's allow you to blacklist mail from/to
particular servers by ip or domain name. The mail in the queue will be
routed to /dev/null after its retry time expires. Unless of course you
don't mind the possibility that verisign could decide to read  your
clients mail each time they make a typho with say yahoo.com and type
something funny.

Routing the ip to /dev/null also saves me bw on my sat link :-D. As some
mail servers of my client's are beyond what I can edit, the null0 route
is the best I can offer them - plus instructions on how to do the reject
of mail in the MTAs considering that I'm not authoritative for .com (so
I can't tell which domains are non-existent without a full lookup via
verisign) and neither am I authoritative for the reverse.

Another thing to note is *lots* of valid e-mail hosts, do not have
reverse dns for their domains. Those that do usually have wrong records.

just my 2cts.

>  
> ken
> 
> 
> 
> ---------------------------------------------
> This service is hosted on the Infocom network
> http://www.infocom.co.ug
-- 
Patrick Okui <[EMAIL PROTECTED]>
Systems Adminstrator
One2Net (U) Ltd



---------------------------------------------
This service is hosted on the Infocom network
http://www.infocom.co.ug

Reply via email to