Early Review of draft-ietf-bfd-stability-13
review-ietf-bfd-stability-13-yangdoctors-early-aries-2024-06-09-00

This is a follow up review to prior -08 version ~3y back.  Prior review
comments were addressed and it looks good from a YD standpoint.  Only a few
minor questions/clarifications below.

1 module in this draft:
- ietf-bfd-stability@2024-05-05.yang

YANG compiler errors or warnings (pyang 2.6.0, yanglint 2.2.8)
- No compiler errors or warnings

Module ietf-bfd-stability@2024-05-05.yang:
- I notice between -08 and -13 that `micro-bfd-ipv6` augments are now removed.
  Is this intentional?
- For all augments that introduce the `lost-packet-count` leaf, these are all
  identical definitions which could leverage a single grouping/uses
  definition.  Any reason not to leverage?

Example validated instance data:

<interfaces xmlns="urn:ietf:params:xml:ns:yang:ietf-interfaces">
  <interface>
    <name>et-0/0/0</name>
    <type
    xmlns:ianaift="urn:ietf:params:xml:ns:yang:iana-if-type">ianaift:ethernetCsmacd</type>
    <oper-status>up</oper-status> <statistics>
      <discontinuity-time>2024-06-09T00:00:00.000+01:00</discontinuity-time>
    </statistics>
  </interface>
  <interface>
    <name>ae0</name>
    <type
    xmlns:ianaift="urn:ietf:params:xml:ns:yang:iana-if-type">ianaift:ieee8023adLag</type>
    <oper-status>up</oper-status> <statistics>
      <discontinuity-time>2024-06-09T00:00:00.000+01:00</discontinuity-time>
    </statistics>
  </interface>
</interfaces>
<routing-state xmlns="urn:ietf:params:xml:ns:yang:ietf-routing">
  <ribs>
    <rib>
      <name>DEFAULT</name>
      <address-family>ipv4</address-family>
    </rib>
  </ribs>
</routing-state>
<routing xmlns="urn:ietf:params:xml:ns:yang:ietf-routing">
  <control-plane-protocols>
    <control-plane-protocol>
      <type
      xmlns:bfd-types="urn:ietf:params:xml:ns:yang:ietf-bfd-types">bfd-types:bfdv1</type>
      <name>DEFAULT</name> <bfd xmlns="urn:ietf:params:xml:ns:yang:ietf-bfd">
        <ip-sh xmlns="urn:ietf:params:xml:ns:yang:ietf-bfd-ip-sh">
          <sessions>
            <session>
              <interface>et-0/0/0</interface>
              <dest-addr>10.1.1.1</dest-addr>
              <authentication>
                <meticulous>true</meticulous>
              </authentication>
              <session-statistics>
                <lost-packet-count
                xmlns="urn:ietf:params:xml:ns:yang:ietf-bfd-stability">10</lost-packet-count>
              </session-statistics>
              <stability
              xmlns="urn:ietf:params:xml:ns:yang:ietf-bfd-stability">true</stability>
            </session>
          </sessions>
        </ip-sh>
        <ip-mh xmlns="urn:ietf:params:xml:ns:yang:ietf-bfd-ip-mh">
          <session-groups>
            <session-group>
              <source-addr>10.2.1.1</source-addr>
              <dest-addr>10.1.1.1</dest-addr>
              <authentication>
                <meticulous>true</meticulous>
              </authentication>
              <rx-ttl>255</rx-ttl>
              <sessions>
                <session-statistics>
                  <lost-packet-count
                  xmlns="urn:ietf:params:xml:ns:yang:ietf-bfd-stability">10</lost-packet-count>
                </session-statistics>
              </sessions>
              <stability
              xmlns="urn:ietf:params:xml:ns:yang:ietf-bfd-stability">true</stability>
            </session-group>
          </session-groups>
        </ip-mh>
        <lag xmlns="urn:ietf:params:xml:ns:yang:ietf-bfd-lag">
          <sessions>
            <session>
              <lag-name>ae0</lag-name>
              <authentication>
                <meticulous>true</meticulous>
              </authentication>
              <use-ipv4>true</use-ipv4>
              <member-links>
                <member-link>et-0/0/0</member-link>
                <micro-bfd-ipv4>
                  <session-statistics>
                    <lost-packet-count
                    xmlns="urn:ietf:params:xml:ns:yang:ietf-bfd-stability">10</lost-packet-count>
                  </session-statistics>
                </micro-bfd-ipv4>
              </member-links>
              <stability
              xmlns="urn:ietf:params:xml:ns:yang:ietf-bfd-stability">true</stability>
            </session>
          </sessions>
        </lag>
        <mpls xmlns="urn:ietf:params:xml:ns:yang:ietf-bfd-mpls">
          <session-groups>
            <session-group>
              <mpls-fec>10.0.0.0/24</mpls-fec>
              <authentication>
                <meticulous>true</meticulous>
              </authentication>
              <sessions>
                <session-statistics>
                  <lost-packet-count
                  xmlns="urn:ietf:params:xml:ns:yang:ietf-bfd-stability">10</lost-packet-count>
                </session-statistics>
              </sessions>
              <stability
              xmlns="urn:ietf:params:xml:ns:yang:ietf-bfd-stability">true</stability>
            </session-group>
          </session-groups>
        </mpls>
      </bfd>
    </control-plane-protocol>
  </control-plane-protocols>
</routing>