Subject: [secdir] Secdir last call review of draft-ietf-opsawg-ntf-09

From: Alexey Melnikov <[email-masked]>
Date: Tue, 26 Oct 2021 11:26:10 +0100

Reviewer: Alexey Melnikov
Review result: Ready

Hi,

I have reviewed this document as part of the security directorate's 
ongoing effort to review all IETF documents being processed by the IESG. 
These comments were written primarily for the benefit of the security 
area directors. Document editors and WG chairs should treat these 
comments just like any other last call comments.

Network telemetry is a technology for gaining network insight and 
facilitating efficient and automated network management. This document 
defines network telemetry as an extension
of Operations, Administration, and Management (OAM) techniques. This 
document clarifies the terminologies and classifies the modules and 
components of a network telemetry system from different perspectives, in 
particilar whether they operate at the control plane, the management 
plane or the forwarding plane. Examples of both IETF and non IETF 
technologies are given.

The document is well written and has a good Security Considerations 
section. As this document is describing a framework, the security 
considerations stay generic, but the Security Considerations covers 
everything I can think of in regards to data confidentiality, privacy, 
access control, etc.

Nits: JSON and XML should have informative references.

Best Regards,

Alexey

---

From: Ben Schwartz <[email-masked]>
Date: Tue, 26 Oct 2021 10:57:11 -0400

On Tue, Oct 26, 2021 at 6:26 AM Alexey Melnikov <[email-masked]>
wrote:
...

>  the Security Considerations covers

I disagree on this point.

The draft mentions privacy in exactly two places.

First, in Background:

>   It is easy to see that network operations can benefit from
>   network big data to gather insights into flows without breaching
>   privacy.

This statement is presented without justification.  I disagree.  If
anything, it is hard to see how network operations can collect "big data"
_without_ breaching privacy.  The techniques described in this draft are
technically identical to the Pervasive Monitoring attack documented in RFC
7258.

Second, in the Security Considerations:

>   In addition to security, privacy is also an important issue.  Network
>   telemetry means to improve the network operation which can ultimately
>   benefit end user's quality of experience.  The network operators must
>   be held accountable and strive for a balance between managing the
>   network and maintaining the user privacy of that network.

I don't think the IETF should be publishing drafts that recommend
compromising user privacy, and I find the qualifications here vague and
toothless.

Although I view these as serious concerns, I think they can be remedied
quite easily.  It seems clear to me that the focus of this draft is on
"technical" networks whose endpoints do not represent users.  When all
endpoints on the network represent a single administrative entity, user
privacy concerns are largely inapplicable.  To that end, I would replace
these two paragraphs with:

> When a network's endpoints do not represent individual users (e.g. in
industrial, datacenter, and infrastructure contexts), network operations
can often benefit from large-scale data collection without breaching user
privacy.

and

> Large-scale network data collection is a major threat to user privacy
[RFC7258].  The Network Telemetry Framework is not applicable to networks
whose endpoints represent individual users, such as general-purpose access
networks.  Any collection or retention of data in those networks must be
tightly limited to protect user privacy.

---

From: Haoyu Song <[email-masked]>
Date: Tue, 26 Oct 2021 17:55:00 +0000

Hi Ben,

Thank you very much for your suggestions! Yes we should make it clear that network telemetry are not applicable to individual end users. I’ll include the new text your proposed in the document.

Best regards,
Haoyu
From: Ben Schwartz <[email-masked]>
Sent: Tuesday, October 26, 2021 7:57 AM
To: Alexey Melnikov <[email-masked]>
Cc: [email-masked]; [email-masked]; [email-masked]
Subject: Re: [secdir] Secdir last call review of draft-ietf-opsawg-ntf-09

On Tue, Oct 26, 2021 at 6:26 AM Alexey Melnikov <[email-masked]<mailto:[email-masked]>> wrote:
...
 the Security Considerations covers
everything I can think of in regards to data confidentiality, privacy,
access control, etc.

>   network big data to gather insights into flows without breaching

This statement is presented without justification.  I disagree.  If anything, it is hard to see how network operations can collect "big data" _without_ breaching privacy.  The techniques described in this draft are technically identical to the Pervasive Monitoring attack documented in RFC 7258.

>   network and maintaining the user privacy of that network.

I don't think the IETF should be publishing drafts that recommend compromising user privacy, and I find the qualifications here vague and toothless.

Although I view these as serious concerns, I think they can be remedied quite easily.  It seems clear to me that the focus of this draft is on "technical" networks whose endpoints do not represent users.  When all endpoints on the network represent a single administrative entity, user privacy concerns are largely inapplicable.  To that end, I would replace these two paragraphs with:

> When a network's endpoints do not represent individual users (e.g. in industrial, datacenter, and infrastructure contexts), network operations can often benefit from large-scale data collection without breaching user privacy.

and

> Large-scale network data collection is a major threat to user privacy [RFC7258].  The Network Telemetry Framework is not applicable to networks whose endpoints represent individual users, such as general-purpose access networks.  Any collection or retention of data in those networks must be tightly limited to protect user privacy.

---

From: Haoyu Song <[email-masked]>
Date: Tue, 26 Oct 2021 18:09:55 +0000

Hi Alexey,

Thank you very much for the review. I'll add informative reference to JSON and XML in the document.

Best regards,
Haoyu

-----Original Message-----
From: Alexey Melnikov <[email-masked]> 
Sent: Tuesday, October 26, 2021 3:26 AM
To: [email-masked]
Cc: [email-masked]; [email-masked]
Subject: Secdir last call review of draft-ietf-opsawg-ntf-09

Hi,

I have reviewed this document as part of the security directorate's ongoing effort to review all IETF documents being processed by the IESG. 
These comments were written primarily for the benefit of the security area directors. Document editors and WG chairs should treat these comments just like any other last call comments.

Network telemetry is a technology for gaining network insight and facilitating efficient and automated network management. This document defines network telemetry as an extension of Operations, Administration, and Management (OAM) techniques. This document clarifies the terminologies and classifies the modules and components of a network telemetry system from different perspectives, in particilar whether they operate at the control plane, the management plane or the forwarding plane. Examples of both IETF and non IETF technologies are given.

The document is well written and has a good Security Considerations section. As this document is describing a framework, the security considerations stay generic, but the Security Considerations covers everything I can think of in regards to data confidentiality, privacy, access control, etc.

Best Regards,

Alexey