Re: [secdir] secdir review of draft-ietf-v6ops-ipv6-cpe-router

Ole Troan <> Wed, 11 August 2010 11:59 UTC

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Subject: Re: [secdir] secdir review of draft-ietf-v6ops-ipv6-cpe-router
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Scott et al,

I'm not entirely sure what the process here is.
do you want to see a new revision of the draft incorporating Scott's comments as well as the feedback we have received from the DHC WG review before we proceed to the IESG review?


> Hi Chris,
> I think your suggestions are reasonable.
> --Scott
> On Thursday, August 5, 2010 8:00am, "Chris Donley" <> said:
>> Scott,
>> If we were to make the following changes to the security section, would they
>> address your concerns?
>> It is considered a best practice to filter obviously malicious
>>   traffic (e.g. spoofed packets, "martian" addresses, etc.).  Thus, the
>>   IPv6 CE router should ought to support basic stateless egress and ingress
>>   filters.  The CE router should is also expected to offer mechanisms to filter
>>   traffic entering the customer network; however, the method by which
>>   vendors implement configurable packet filtering is beyond the scope
>>   of this document.
>>   Security requirements:
>>   S-1:  The IPv6 CE router SHOULD support
>>         [I-D.ietf-v6ops-cpe-simple-security]. In particular, the IPv6 CE router
>> SHOULD support functionality sufficient for implementing the set of
>> recommendations in [I-D.ietf-v6ops-cpe-simple-security] Section 4.  This
>> document takes no position on whether such functionality is enabled by
>> default or mechanisms by which users would configure it.
>>   S-2:  The IPv6 CE router MUST support ingress filtering in accordance
>>         with [RFC2827] (BCP 38)
>> Also, since we're so late in the process, my preference would be to specify device
>> security as part of our Phase 2 draft (scheduled to start work on 8/13).  Would
>> you have any issue with that?
>> Chris
>> -----Original Message-----
>> From: Scott G. Kelly []
>> Sent: Tuesday, August 03, 2010 3:32 PM
>> To: Ole Troan
>> Cc:;;
>> Subject: Re: secdir review of draft-ietf-v6ops-ipv6-cpe-router
>> Hi Ole,
>> On Monday, August 2, 2010 5:58am, "Ole Troan" <> said:
>> <trimmed...>
>>>> The security considerations section begins with a paragraph stating that basic
>>>> stateless egress and ingress filters should be supported (lowercase "should"),
>>>> and goes on to say that the CE router should offer mechanisms to filter traffic
>>>> entering the customer network, but that how these are implemented is out of
>>>> scope
>>>> (lowercase "should").
>>> we tried to limit RFC2119 language to only the numbered requirements. the
>>> initial
>>> paragraph is only to set the stage for the more detailed requirements below.
>>> basically just saying that the CPE should support a packet filtering capability.
>>> but from a security point of view I'm not sure if we can state this in very much
>>> more concrete terms?
>> Okay, I guess it makes more sense when viewed as introductory text for the
>> numbered requirements.
>>>> Then, it has the following statements:
>>>>  Security requirements:
>>>>  S-1:  The IPv6 CE router SHOULD support
>>>>        [I-D.ietf-v6ops-cpe-simple-security].
>>>>  S-2:  The IPv6 CE router MUST support ingress filtering in accordance
>>>>        with [RFC2827] (BCP 38)
>>>> When I first read this, I thought the statements in the first paragraph were
>>>> somewhat weak and imprecise, as they don't use RFC2119 language. When I read
>>>> draft-ietf-v6ops-cpe-simple-security-12.txt, I thought that document gives a
>>>> relatively thorough treatment of security considerations, but I'm not sure what
>>>> it means to say "The IPv6 CE router SHOULD support" it.
>>> the intention was to state the the CPE router should have the capability of
>>> doing
>>> the functions described in the simple security draft. but we did not want to
>>> make
>>> any recommendation what the default should be. I believe recommending that
>>> simple
>>> security is enabled by default in a CPE routers would violate the Internet
>>> architecture principles. would it help if we changed the text to:
>>> S-1: The IPv6 CE router SHOULD support the [I-D.ietf-v6ops-cpe-simple-security].
>>> This functionality MUST be user configurable and this
>>>        specification makes no recommendation what the default setting should
>>> be.
>> Since the referenced draft is informational and does not mandate any behavior (it
>> only makes non-binding recommendations), I'm still confused about what it means to
>> "support" it - it seems very difficult to pin down. Do you mean that these devices
>> MUST provide knobs for all capabilities defined there, or just some of them (and
>> if so, which ones)?
>> Since both of these documents are informational, perhaps it doesn't matter, but it
>> seems like we'd be doing the user community a better service if we took a definite
>> position on baseline security requirements for these devices.
>> <more trimmed...>
>>> while on the topic of security. we should perhaps have said something more about
>>> device security. as in requirements for access to the device itself. today many
>>> of
>>> these routers allow telnet and http access, more often than not with default
>>> password. where they also make a distinction between 'inside' and 'outside',
>>> which
>>> some recent attacks have taken advantage of.
>> The simple security document does reference management applications (section 3.5),
>> but only states that they should not be accessible on the WAN interface by
>> default. It might be worthwhile to update it according to your thoughts above.
>> --Scott