North American Network Operators Group

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69/8 is harder to fix than it looks at first glance

  • From: Michael.Dillon
  • Date: Wed Mar 12 12:13:35 2003

> the problem is simple:  outdated filters.

Agreed, more or less.

> the solution is simple:  tell people that their filters are out of date

Sorry, but this fixes nothing. It notifies people that a problem exists 
but it doesn't fix the filters.

Several things need to be done for a lasting fix.

- we need to identify where the broken filters are.
- we need to find contact information for all those places.
- we need to notify all the places that their filters are broken.

Already, this is a heck of a lot of work and I would not describe this as 
a simple solution. But now the real fun begins because all of those people 
that were notified will reply.

- some will tentatively accept your info but ask for proof that their 
filter is broken.
- some will strongly deny that anything is wrong with their filters
- some will ask what will fix their broken filter
- some will ask whether your fix is short term or whether it is general 
enough to handle similar issues

And therein lies the crux of the problem. We have no good answer to this 
last one other than to tell these people to change their filters today and 
then to regularly hunt through some mailing lists or websites to find 
notifications that the filters need to be changed again. And again. And 
again and again and again.

When does it stop?

The fact is that are operating these 21st century networks using 19th 
century business technology. This does not scale. The net is too big to be 
managed by person to person exchange of information. That's why we have 
DNS protocols instead of issuing updated copies of the hosts file. And 
that's why we need an automated system to publish current status of IP 
address ranges in a format that would be acceptable to firewall admins and 
firewall vendors.

These people already trust LDAP enough to use it for distributing keys and 
certificates. IP address range attributes are similar sorts of out-of-band 
information that is not essential to packet forwarding but needs to be 
distributed in order to configure devices correctly. In this case, the 
attribute that we are primarily interested in distributing is whether or 
not an IP address range has been allocated by ARIN for use or not. But 
there are other useful attributes that could be distributed as well such 
as contact information.

Let's all stop this lazy style of knee-jerk engineering that assumes all 
problems are simple and can be solved using a router and some PERL 
scripts. Some problems are hard technically and socially. These kinds of 
problems can only be solved if you are willing to look at the big picture 
as well as the immediate impacts.

--Michael Dillon