Re: [secdir] [tcpm] SECDIR REVIEW of draft-ietf-tcpm-icmp-attacks-10.txt
"Anantha Ramaiah (ananth)" <ananth@cisco.com> Mon, 15 February 2010 22:30 UTC
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Date: Mon, 15 Feb 2010 14:32:17 -0800
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Thread-Topic: [tcpm] SECDIR REVIEW of draft-ietf-tcpm-icmp-attacks-10.txt
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From: "Anantha Ramaiah (ananth)" <ananth@cisco.com>
To: Fernando Gont <fernando@gont.com.ar>, Phillip Hallam-Baker <hallam@gmail.com>
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Cc: tcpm@ietf.org, secdir@ietf.org
Subject: Re: [secdir] [tcpm] SECDIR REVIEW of draft-ietf-tcpm-icmp-attacks-10.txt
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Some general comments on this discussion inline... > -----Original Message----- > From: tcpm-bounces@ietf.org [mailto:tcpm-bounces@ietf.org] On > Behalf Of Fernando Gont > Sent: Monday, February 15, 2010 11:50 AM > To: Phillip Hallam-Baker > Cc: tcpm@ietf.org; secdir@ietf.org > Subject: Re: [tcpm] SECDIR REVIEW of > draft-ietf-tcpm-icmp-attacks-10.txt > > Hello, Phillip, > > Thanks so much for your feedback! See my comments inline.... > > > > The principal security risks considered are service risks. > ICMP may be > > used to perform certain denial of service and performance downgrade > > attacks. As such it probably needs rather more > justification than 'we > > have always done this' when building critical infrastructures. > > I fully agree. This I-D has been debated in tcpm form... 6 > years now. It was originally meant for Std track, but somehow > ended up heading for Informational. What's in the I-D is what > most implementation (all the mainstream ones, at least) do. That is true. Many implementations already do what is being said in this ID. > > So if *I* had to answer why we don't stress that ICMP should > be disregarded in many scenarios, etc., I can just say that > this is what the WG has converged to. I think you should put some text to this effect. IMO, we don't have an overwhelming consensus on whether this document should be informational or standard. To me, I have no issues making this head towards the PS, one of the main reasons being it has been well adopted in the internet today. I also agree that "just being popular" doesn't imply that it needs to become a standard. In this case it is not only popular, these mitigations have more pros than cons. <snip> > > This argument is > > almost made on page 15. Some statement giving the case for taking > > notice of ICMP messages at all is in order. > > I guess the "statement" that you could get here (tcpm) is > "responsiveness". -- with which I'd disagree, for many of the > reasons stated in the draft, and because in many other cases > it has been argued in this very wg that "tcp is supposed to > be robust, it's not optimized for any scenario, etc.". > > Should I craft some text along the lines of "responsiveness"? That may be a good idea. > > > > > It might well be that an > > appropriate control in certain cases would be to turn off ICMP hard > > errors and rely on timeouts, I am thinking here of critical > > infrastructure applications and communications between > hosts running > > BGP functions. > > Most (if not all) real-world implementations already do this. > We have lived with this behaviour that you describe for the > last..mm.. 20 years (or so) with BSDs... and there's no way > that BSDs, or Linux, or Cisco, or whoever are going to change > back their implementations to e.g. > "resetting connections in response to ICMP hard errors". For > instance, they have issued vulnerability advisories in this respect... Correct. Thanks, -Anantha
- [secdir] SECDIR REVIEW of draft-ietf-tcpm-icmp-at… Phillip Hallam-Baker
- Re: [secdir] [tcpm] SECDIR REVIEW of draft-ietf-t… Lars Eggert
- Re: [secdir] [tcpm] SECDIR REVIEW of draft-ietf-t… Joe Touch
- Re: [secdir] [tcpm] SECDIR REVIEW of draft-ietf-t… Joe Touch
- Re: [secdir] [tcpm] SECDIR REVIEW of draft-ietf-t… Anantha Ramaiah (ananth)
- Re: [secdir] SECDIR REVIEW of draft-ietf-tcpm-icm… Fernando Gont
- Re: [secdir] [tcpm] SECDIR REVIEW of draft-ietf-t… Fernando Gont
- Re: [secdir] [tcpm] SECDIR REVIEW of draft-ietf-t… Fernando Gont
- Re: [secdir] [tcpm] SECDIR REVIEW of draft-ietf-t… Joe Touch
- Re: [secdir] [tcpm] SECDIR REVIEW of draft-ietf-t… Anantha Ramaiah (ananth)
- Re: [secdir] [tcpm] SECDIR REVIEW of draft-ietf-t… Joe Touch
- Re: [secdir] [tcpm] SECDIR REVIEW of draft-ietf-t… Phillip Hallam-Baker
- Re: [secdir] [tcpm] SECDIR REVIEW of draft-ietf-t… Joe Touch