The data model defined in this document is a massive piece of work: it consists of 11 YANG modules and defines around 1200 schema nodes. The "ietf-ospf@2017-10-30" module is compatible with the NMDA architecture. **** Comments 1. Unless there is a really compelling reason not to do so, the "ietf-ospf" should declare YANG version 1.1. For one, "ietf-routing" that is being augmented by "ietf-ospf" already declares this version. Some of my suggestions below also assume version 1.1. 2. The "ietf-ospf" can work only with the new NMDA-compatible revisions of some modules, such as "ietf-interfaces" and "ietf-routing". I understand it is not desirable to import such modules by revision, but at least it should be mentioned in a description attached to every such import. 3. Maybe the draft could mention that implementations should supply a default routing domain as a system-controlled resource. 4. In "when" expressions, the module uses literal strings for identities. This is known to be problematic, the XPath functions derived-from() or derived-from-or-self() should be used instead. 5. Some enumerations, such as "packet-type" and "if-state-type" define enum identifiers with uppercase letters and/or underscores, for example "Database-Description" or "LONG_WAIT". RFC6087bis recommends that only lowercase letters, numbers and dashes. I think this convention should be observed despite the fact that the current names are traditionally used in OSPF specs. The "ietf-routing" module also defines "router-id" even though the documents use "Router ID". 6. The types of LSA headers are modelled as integers. While OSPF gurus probably know these numbers by heart, it is not very reader-frienly. So at least some references to documents defining these numbers should be provided, but my suggestion is to consider implementing them with identities. It seems it might also be useful to define some "abstract" identities for these types. For example, if "opaque-lsa" is defined, then the definition of container "opaque" could simply use when "derived-from(../../header/type, 'ospf:opaque-lsa')"; instead of when "../../header/type = 9 or " + "../../header/type = 10 or " + "../../header/type = 11"; 7. The title of sec. 2.9 should be "OSPF Notifications" rather than "OSPF notification".