What would the ip-blocking BGP feed accomplish? Spoofed source addresses are a staple of the DNS cache poisoning attack. Worst case scenario, you've opened yourself up to a new avenue of attack where you're nameservers are receiving spoofed packets intended to trigger a blackhole filter, blocking communication between your network and the legitimate owner of the forged ip address. Michael Smith wrote:
Hello All:
From: Paul Vixie <vixie@isc.org> Date: Tue, 29 Jul 2008 01:24:43 +0000 To: Nanog <nanog@merit.edu> Subject: Re: Great Suggestion for the DNS problem...?
jra@baylink.com ("Jay R. Ashworth") writes:
[ unthreaded to encourage discussion ]
On Sat, Jul 26, 2008 at 04:55:23PM -0500, James Hess wrote:
Nameservers could incorporate poison detection...
Listen on 200 random fake ports (in addition to the true query ports); if a response ever arrives at a fake port, then it must be an attack, read the "identified" attack packet, log the attack event, mark the RRs mentioned in the packet as "poison being attempted" for 6 hours; for such domains always request and collect _two_ good responses (instead of one), with a 60 second timeout, before caching a lookup.
The attacker must now guess nearly 64-bits in a short amount of time, to be successful. Once a good lookup is received, discard the normal TTL and hold the good answer cached and immutable, for 6 hours (_then_ start decreasing the TTL normally).
Is there any reason which I'm too far down the food chain to see why that's not a fantastic idea? Or at least, something inspired by it?
at first glance, this is brilliant, though with some unimportant nits.
however, since it is off-topic for nanog, i'm going to forward it to the namedroppers@ops.ietf.org mailing list and make detailed comments there. --
Still off topic, but perhaps a BGP feed from Cymru or similar to block IP addresses on the list?
Regards,
Mike