Last Call Review of draft-ietf-dnsop-root-loopback-02
review-ietf-dnsop-root-loopback-02-secdir-lc-lepinski-2015-09-17-00

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.

This draft is essentially ready for publication (with minor comments below).

This is an Informational document that specifies how the operator of a
recursive resolver could run a copy of the root zone on a loopback interface.
The purpose of this mechanism are two-fold: (1) to speed response time in the
case of a negative response from the root zone; (2) to hide queries to the root
zone from malicious observers.

The security story for this mechanism is essentially:

A) Since this mechanism must be run on a loopback interface, there is
no possibility that the mechanism will negatively impact other entities. (I.e.,
it would be bad if a recursive resolver started giving authoritative answers
for the root zone to anyone other than itself.)

B) DNSSEC is used to ensure that the answers provided by this mechanism are
valid.

The security considerations section for this document is somewhat terse and I
believe the document could be improved by expanding that section. In
particular, I believe that point (A) above should be stated explicitly in the
security considerations section. (That is, it is stated elsewhere in the
document that using a loopback mechanism is essential. However, I think that
repeating that in the security considerations section would be helpful -- I
think that point is an important part of the story for why this mechanism
doesn't break things.)

Additionally, in the security considerations section, the authors are somewhat
brief in describing the need for DNSSEC. I think that is fine, but given the
brevity, I think it would be helpful to have a citation to another document
that describes why DNSSEC is needed. (Is RFC 4033 the best reference regarding
what DNSSEC protects against? Or is there a better document now?)

- Matt Lepinski