nanog mailing list archives
Re: Rate of growth on IPv6 not fast enough?
From: Owen DeLong <owen () delong com>
Date: Tue, 20 Apr 2010 21:27:14 -0700
On Apr 20, 2010, at 6:34 PM, Karl Auer wrote:
On Tue, 2010-04-20 at 12:59 -0700, Owen DeLong wrote:On Apr 20, 2010, at 12:31 PM, Roger Marquis wrote:NAT _always_ fails-closedStateful Inspection can be implemented fail-closed.Not to take issue with either statement in particular, but I think there needs to be some consideration of what "fail" means.
I believe we are talking about the case where some engineer fat-fingers a change and Roger's claim is that a stateful inspection without NAT box will permit unintended traffic while a NAT box will not. My claim is that the stateful inspection box can be implemented such that it has an equally secure set of failure modes for fat-fingering to a NAT+stateful inspection device.
Reading through the security alerts from any vendor is a pretty sobering process - stuff fails open more often than you might expect.
Yep.
So I think we should be very cautious about saying that things "fail open" or "fail closed".
My point is not that they do or do not fail closed, but, that a well designed SI firewall will fail with the exact same security risks as a NAT device.
We should be especially cautious about it when the functionality we are interested in is really no more than a happy side effect of some other functionality. NAT's "security", to the extent that it exists at all, is a side effect of what it is intended to do, which is translate and map addresses.
IOW, All of NAT's security comes from the fact that it requires a state table, like stateful inspection. Owen
Current thread:
- Re: Rate of growth on IPv6 not fast enough?, (continued)
- Re: Rate of growth on IPv6 not fast enough? Mark Smith (Apr 20)
- Re: Rate of growth on IPv6 not fast enough? Dave Pooser (Apr 20)
- Re: Rate of growth on IPv6 not fast enough? Owen DeLong (Apr 20)
- Re: Rate of growth on IPv6 not fast enough? Mark Smith (Apr 21)
- Re: Rate of growth on IPv6 not fast enough? Jim Burwell (Apr 21)
- Re: Rate of growth on IPv6 not fast enough? Dave Sparro (Apr 21)
- Re: Rate of growth on IPv6 not fast enough? Cutler James R (Apr 21)
- Re: Rate of growth on IPv6 not fast enough? Jack Bates (Apr 21)
- Re: Rate of growth on IPv6 not fast enough? Karl Auer (Apr 20)
- Re: Rate of growth on IPv6 not fast enough? joel jaeggli (Apr 20)
- Re: Rate of growth on IPv6 not fast enough? Owen DeLong (Apr 20)
- Re: Rate of growth on IPv6 not fast enough? Mark Andrews (Apr 20)
- Re: Rate of growth on IPv6 not fast enough? Karl Auer (Apr 20)
- Re: Rate of growth on IPv6 not fast enough? joel jaeggli (Apr 20)
- Re: Rate of growth on IPv6 not fast enough? William Herrin (Apr 21)
- Re: Rate of growth on IPv6 not fast enough? Mark Smith (Apr 29)
- Re: Rate of growth on IPv6 not fast enough? isabel dias (Apr 29)
- Re: Rate of growth on IPv6 not fast enough? William Herrin (Apr 29)
- Re: Rate of growth on IPv6 not fast enough? Valdis . Kletnieks (Apr 29)