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Re: do bogon filters still help?
From: Kevin Loch <kloch () hotnic net>
Date: Thu, 12 Jan 2006 10:58:15 -0500


Florian Weimer wrote:
* Pim van Pelt:
Hi, here's a member of 'the folks at bit.nl'.  Just a quick note to
say that we have been sourcing IPv4 packets from 192.88.99.1 at a rate
of 2.000 to 10.000 packets per second since early 2003, so I'm guessing we have sent some 750.000 billion packets by now.

And this is just so wrong.  You should use an address you own as a
source address.  Otherwise, packets tend to get dropped by filters.

Wouldn't you expect to see packets return from the same address
you send them to?  ICMP and stateful firewalls work much better
that way.   Our 6to4 relay also soucres packets from 192.88.99.1,
it seems to work best that way.

Don't filter 192.88.99.1 in any direction unless you want to
break 6to4.  If you want to limit your exposure you could
allow only proto 41 and icmp packets and not break it.

If you have native IPv6 on your network you could run
a local 6to4 relay for your customers and filter 192.88.99.0/24
to/from your peers.

- Kevin


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