[AusNOG] Bogon Filtering

[Geoff Huston]

On 13/02/2012, at 4:31 PM, Mark Newton wrote:

> On Mon, Feb 13, 2012 at 04:22:45PM +1100, Chris Killian wrote:
> 
>> Fairly open ended question but does filter these anymore. *Some companies
>> seem to think that as the IPV4 space has been fully allocated this is no
>> longer a requirement. However looking at the bogon lists there are still a
>> huge number of unallocted IPV4 address.
>> What do you guys think.
> 
> As someone who has had to spend weeks of his life on several 
> occasions trying to convince networks utilizing bogon filtering to 
> update themselves because APNIC had started allocating out of a 
> new IANA /8 block, I can tell you that anyone who is still bogon
> filtering is causing more harm than good, both to themselves and to
> whatever passes for global internet connectivity these days.
> 
> What problem does bogon filtering solve?  Nothing that can't also
> be solved with less effort by using firewalls, Ironports, and
> other layer-5+ techniques.

These bogon filters, when they get out of date, are really difficult to 
detect. We've been trying an approach (http://labs.apnic.net/blabs/?p=68)
but it's by no means ideal.

  Geoff Huston
  APNIC