North American Network Operators Group

Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical

Re: Question concerning authoritative bodies.

  • From: jlewis
  • Date: Tue Mar 11 11:09:37 2003

On Tue, 11 Mar 2003, Ron da Silva wrote:

> Hmm...I would argue that every operator needs to run their own DNSBL.

Can you elaborate on why?  IMO, there are definite benefits to 
centralized, shared DNSBLs, especially if testing is involved.  Many can 
benefit from the work done by a few and not have to duplicate the work.

If you only DNSBL IPs after you receive spam from them, you have to get 
spammed by every IP before it's blocked.  Why not reject mail from IPs 
that have spammed others before they spam you and your customers?  Though 
I have problems with the way it's been run, I think that's the idea behind 
bl.spamcop.net.  If they could just restrict nominations to a more clueful 
group of users, such a system could be very effective for blocking spam 
everywhere as soon as one system gets hit.  For spam from open relays and 
proxies, a centralized DNSBL that tests the IPs that talk to servers using 
it can be just as, if not more, effective.

> It would be very difficult to convince any operator to give up control
> of defining their own DNSBL (or even not having one at all).

You can use a central DNSBL without giving up total control.  Shortly 
after I configured servers to use a DNSBL for the first time, I recognized 
the need for a local DNSWL and have continued to use one ever since.  When 
I setup other people's servers to use DNSBLs, I help them setup a DNSWL 
and explain how to maintain it.
 
----------------------------------------------------------------------
 Jon Lewis *[email protected]*|  I route
 System Administrator        |  therefore you are
 Atlantic Net                |  
_________ http://www.lewis.org/~jlewis/pgp for PGP public key_________