Last Call Review of draft-ietf-bfd-yang-09
review-ietf-bfd-yang-09-secdir-lc-huitema-2018-02-01-00

Request Review of draft-ietf-bfd-yang
Requested revision No specific revision (document currently at 17)
Type Last Call Review
Team Security Area Directorate (secdir)
Deadline 2018-02-09
Requested 2018-01-24
Requested by Jeffrey Haas
Authors Reshad Rahman , Lianshu Zheng , Mahesh Jethanandani , Santosh Pallagatti , Greg Mirsky
I-D last updated 2018-02-01
Completed reviews Secdir Last Call review of -09 by Christian Huitema (diff)
Rtgdir Last Call review of -09 by Ravi Singh (diff)
Yangdoctors Last Call review of -09 by Jürgen Schönwälder (diff)
Genart Last Call review of -14 by Meral Shirazipour (diff)
Secdir Last Call review of -14 by Christian Huitema (diff)
Comments 
The BFD Yang module is a dependency for several routing-area drafts.  This interwork with those drafts, particularly with regards to session configuration, may have security implications that should be examined in tandem with the importing yang module.

The routing area directorate is requested to specifically examine interwork/usability of the BFD yang module with regards to the importing protocol yang modules.

It is understood that the deadline is likely overly aggressive, but was chosen to coincide mostly with the BFD WGLC on this document.  This document has been reviewed for BFD usability several times and is otherwise considered mature.
Assignment Reviewer Christian Huitema
State Completed Snapshot
Review review-ietf-bfd-yang-09-secdir-lc-huitema-2018-02-01
Reviewed revision 09 (document currently at 17)
Result Ready
Completed 2018-02-21
The information below is for an old version of the document.
review-ietf-bfd-yang-09-secdir-lc-huitema-2018-02-01-00
Christian, thank you for the review.

Regarding the concern expressed below, the alarm is issued at the other end via
the Notifications (section 2.3).

Regards,
Reshad.

On 2018-02-01, 5:39 PM, "Christian Huitema" <huitema@huitema.net> wrote:

    Reviewer: Christian Huitema
    Review result: Has Nits

    BFD, defined in RFC5880, is a protocol intended to detect faults in the
    bidirectional path between two forwarding engines, including interfaces,
    data link(s), and to the extent possible the forwarding engines themselves,
    with potentially very low latency. The Yang module defined in this draft
    enables management of this protocol, such as toggling parameters or
    receiving notifications.

    As stated in the security section, the module is "to be accessed via the
    NETCONF protocol [RFC6241]", and as such its security is pretty much tied to
    that of NETCONF.

    My only nit comes from reading section 6.8.16 of RFC 5880, about
    "Administrative Control". This points to an obvious issue when the
    administrator of a router disables BFD on a particular link, either by
    mistake or by malice. This will make future failures harder to notify, and
    can affect operation of the network. Nothing much can be done about that on
    the node itself, but I would expect that disabling BFD would raise some
    kind of alarm at the other end of the link. I did not understand how that
    alarm is described in the Yang module, but that may be because I am not all
    that familiar with Yang.