Reviewer: Ebben Aries Review result: On the Right Track 1 module in this draft: - ietf-isis@xxxxxxxxxxxxxxx No YANG compiler errors or warnings (from pyang 1.7.5 and yanglint 0.16.54) "ietf-isis@2018-08-09" module is compatible with the NMDA architecture. Module ietf-isis@xxxxxxxxxxxxxxx: - Both the description and the draft name reference that this module is specific to configuration but contains operational state nodes in addition to RPCs and notifications. Any wording suggesting this is only configuration should be changed - Module description must contain most recent copyright notice per https://tools.ietf.org/html/draft-ietf-netmod-rfc6087bis-20#section-3.1 - Module description reads "common across all of the vendor implementations". I don't think this needs to be called out as such as that is the overall intention of *all* IETF models - This module contains '22' features (and the respective OSPF module currently contains '26'). While it is understood the purpose of these features in the module, take precaution as to complexity for clients if they need to understand >= quantity of features per module in use on a network-element. We are going to end up w/ feature explosion to convey *all* possible features of each network-element leading to divergence back towards native models at the end of the day. A large amount of these feature names could be defined within a more global namespace (e.g. nsr) but this gives us a granular yet cumbersome approach (e.g. feature isis:nsr, ospf:nsr, etc..) - RPC 'clear-adjacency' does not have any input leaf that covers clearing a specific neighbor/adjacency (See comments below as well regarding RPC alignment w/ the OSPF model) - RPC 'clear-adjacency' has an input node of 'interface' however this is just a string type. Is there any reason this is not a leafref/if:interface-ref (much like in the OSPF model) - Child nodes within a container or list SHOULD NOT replicate the parent identifier per https://tools.ietf.org/html/draft-ietf-netmod-rfc6087bis-20#section-4.3.1. A case in point is the list /afs/af that has a leaf of 'af' <afs> <af> <af>ipv4</af> <enable>true</enable> </af> </afs> Not only is this replication, but we should likely not abbreviate 'afs' if we are using the expanded 'address-family' in other IETF models such as ietf-i2rs-rib General comments on the draft + nits: - Since YANG tree diagrams are used, please include an informative reference per https://tools.ietf.org/html/draft-ietf-netmod-rfc6087bis-20#section-3.4 - Section 1.1 does not need to exist since this would be covered by the reference mentioned above - Reference to NMDA compliance should be contained within Section 1 (vs. Section 2) per https://tools.ietf.org/html/draft-ietf-netmod-rfc6087bis-20#section-3.5 - Section 2: It seems reference should be given to the location of where the ietf-routing module is defined (As well as reference to NMDA RFC in the above reference) - Section 2.1: "Additional modules may be created this to support..." needs slight rewording adjustment - Section 3: The RPC operations are named 'clear-adjacency' and 'clear-database' rather w/ reliance off namespacing for uniqueness. This section refers to 'clear-isis-database' and 'clear-isis-adjacency' - Section 4: Notification name mismatch in this section from actual naming within the module (e.g. 'adjacency-change' should rather be 'adjacency-state-change') - Section 7: Security Considerations will need updating to be patterned after the latest version of the template at https://trac.ietf.org/trac/ops/wiki/yang-security-guidelines per https://tools.ietf.org/html/draft-ietf-netmod-rfc6087bis-20#section-3.7 - Section 12: All modules imported within this module MUST be referenced within this section per https://tools.ietf.org/html/draft-ietf-netmod-rfc6087bis-20#section-3.9. There are quite a few missing from this section right now - Appendix A: Some of the XML elements are off in alignment - Appendix A: Examples must be validated. The example given has the following issues: - /routing[name='SLI'] and /routing/description are invalid data nodes and do not exist. I'm not sure why they are in the XML example here - The example is meant to reference configuration however /routing/interfaces is a r/o container - The control-plane-protocol 'type' needs to be qualified - e.g. <type xmlns:isis="urn:ietf:params:xml:ns:yang:ietf-isis">isis:isis</type> - The area-address does not validate against the pattern regex and must end with a '.' e.g. <area-address>49.0001.0000.</area-address> - metric-type/value is set to 'wide' which is invalid. This should rather be 'wide-only' - isis/afs/af/af is set to 'ipv4-unicast' which is invalid. This should rather be 'ipv4' per iana-routing-types - /interfaces/interface/type must be populated and is invalid. This should rather be qualified as such: <type xmlns:ianaift="urn:ietf:params:xml:ns:yang:iana-if-type">ianaift:softwareLoopback</type> <type xmlns:ianaift="urn:ietf:params:xml:ns:yang:iana-if-type">ianaift:ethernetCsmacd</type> - /interfaces/interface/link-up-down-trap-enable must have a value associated as such: <link-up-down-trap-enable>enabled</link-up-down-trap-enable> - NP container 'priority' has a must statement checking if an interface-type is set to 'broadcast' however if you take the XML example from this section, it will fail to validate even if <priority> is not defined underneath an interface-type of 'point-to-point'. It seems to me that this logic may need to be readjusted or not exist at all (priority can still be set on implementations on loopback interfaces - which would default to 'broadcast' in the example here). Could you not solve this with use of 'when' vs. 'must' as such: when '../interface-type = "broadcast"' { description "Priority can only be set for broadcast interfaces."; } https://tools.ietf.org/html/draft-ietf-netmod-rfc6087bis-20#section-4.18.2. - /interfaces/interface/ipv4/mtu must contain a valid value (and likely not need to be defined for Loopback0) - 'isis/mpls-te/ipv4-router-id' is invalid and should rather be 'isis/mpls/te-rid/ipv4-router-id' - 'isis/afs/af/enabled' is invalid and should rather be 'isis/afs/af/enable' - Examples should use IPv6 addresses where appropriate per https://tools.ietf.org/html/draft-ietf-netmod-rfc6087bis-20#section-3.12. - Looking at the latest revision of ietf-ospf (draft-ietf-ospf-yang-17) and some comments performed earlier this year, I would suggest that for where there are similarities that descriptions should be aligned both within the same module and across modules Examples: # ietf-isis container node-tags { if-feature node-tag; list node-tag { leaf tag { type uint32; description "Node tag value."; } description "List of tags."; } description "Node Tag container"; } ... container node-tags { if-feature node-tag; list node-tag { key tag; leaf tag { type uint32; description "Node tag value."; } description "List of tags."; } description "Container for node tags."; } # ietf-ospf container node-tags { if-feature node-tag; list node-tag { key tag; leaf tag { type uint32; description "Node tag value."; } description "List of tags."; } description "Container for node admin tags."; } * Note: This is seen for other like leafs as well (e.g. short-delay, long-delay, etc..) - Suggest alignment of attributes across RPCs from ietf-isis and ietf-ospf (e.g. ietf-ospf currently defines generic actions with a 'routing-protocol-name' as an argument vs. protocol specific with 'routing-protocol-instance-name')
