Adding OpenConfig YANG models.

Change-Id: I0a2fdd5826e80933cf4b9ae939ff3051acec02aa
diff --git a/models/openconfig/src/main/yang/network-instance/openconfig-network-instance-l3.yang b/models/openconfig/src/main/yang/network-instance/openconfig-network-instance-l3.yang
new file mode 100644
index 0000000..72fb8af
--- /dev/null
+++ b/models/openconfig/src/main/yang/network-instance/openconfig-network-instance-l3.yang
@@ -0,0 +1,112 @@
+module openconfig-network-instance-l3 {
+
+  yang-version "1";
+
+  // namespace
+  namespace "http://openconfig.net/yang/network-instance-l3";
+
+  prefix "oc-ni-l3";
+
+  // import some basic types
+  //import ietf-inet-types { prefix inet; }
+  import openconfig-extensions { prefix "oc-ext"; }
+  import openconfig-types { prefix "octypes"; }
+
+  // meta
+  organization "OpenConfig working group";
+
+  contact
+    "OpenConfig working group
+    www.openconfig.net";
+
+  description
+    "This module contains groupings which specifically relate to
+    Layer 2 network instance configuration and operational state
+    parameters.";
+
+  oc-ext:openconfig-version "0.8.0";
+
+  revision "2017-02-28" {
+    description
+      "Add OSPFv2 to network instance";
+    reference "0.8.0";
+  }
+
+  revision "2017-01-26" {
+    description
+      "Add policy forwarding to network instance";
+    reference "0.7.0";
+  }
+    
+  revision "2017-01-13" {
+    description
+      "Add AFT to the network instance";
+    reference "0.6.0";
+  }
+
+  revision "2016-12-15" {
+    description
+      "Add segment routing to network instance";
+    reference "0.5.0";
+  }
+
+  revision "2016-11-10" {
+    description
+      "Update model to include IS-IS.";
+    reference "0.4.1";
+  }
+
+  revision "2016-09-28" {
+    description
+      "Change L2 instance to submodule; add MAC table";
+    reference "0.3.0";
+  }
+
+  revision "2016-08-11" {
+    description
+      "Resolve repeated container names in routing protocols";
+    reference "0.2.3";
+  }
+
+  revision "2016-07-08" {
+    description
+      "Updated with refactored routing protocol models";
+    reference "0.2.1";
+  }
+
+  revision "2016-03-29" {
+    description
+      "Initial revision";
+    reference "0.2.0";
+  }
+
+  revision "2016-03-14" {
+    description
+      "Initial revision";
+    reference "0.1.0";
+  }
+
+  grouping l3ni-instance {
+    description
+      "Configuration and operational state parameters relevant
+      to network instances that include a Layer 3 type";
+
+  }
+
+  grouping l3ni-instance-common-config {
+    description
+      "Configuration parameters that are common to L3 network
+      instances other than the default instance";
+
+    leaf-list enabled-address-families {
+      type identityref {
+        base octypes:ADDRESS_FAMILY;
+      }
+      description
+        "The address families that are to be enabled for this
+        network instance.";
+    }
+  }
+
+
+}