diff --git a/.gitmodules b/.gitmodules
index 3d2a8e3f7a1d..e2a581d6a8b8 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -34,7 +34,7 @@
 	url = https://github.com/p4lang/ptf.git
 [submodule "src/sonic-utilities"]
 	path = src/sonic-utilities
-	url = https://github.com/Azure/sonic-utilities
+	url = https://github.com/zhenggen-xu/sonic-utilities
 [submodule "platform/broadcom/sonic-platform-modules-arista"]
 	path = platform/broadcom/sonic-platform-modules-arista
 	url = https://github.com/aristanetworks/sonic
diff --git a/src/sonic-yang-mgmt/test_code/yangModelTesting.py b/src/sonic-yang-mgmt/test_code/yangModelTesting.py
new file mode 100644
index 000000000000..8a20578c247e
--- /dev/null
+++ b/src/sonic-yang-mgmt/test_code/yangModelTesting.py
@@ -0,0 +1,67 @@
+import yang as ly
+import sonic_yang as sy
+import logging
+
+from os import listdir
+from os.path import isfile, join, splitext
+
+logging.basicConfig(level=logging.DEBUG)
+log = logging.getLogger(":")
+log.setLevel(logging.DEBUG)
+log.addHandler(logging.NullHandler())
+
+def main():
+
+    yangDir = "/sonic/src/sonic-yang-mgmt/models"
+    yangDataInst = yangDir + "/sonic_config_data.json"
+    
+    # get all files
+    yangFiles = [f for f in listdir(yangDir) if isfile(join(yangDir, f))]
+    # get all yang files
+    yangFiles = [f for f in yangFiles if splitext(f)[-1].lower()==".yang"]
+    yangFiles = [f.split('.')[0] for f in yangFiles]
+
+    # load yang mdoules
+    ctx = ly.Context(yangDir)
+    for f in yangFiles:
+        # load a module m
+        m = ctx.get_module(f)
+        if m is not None:
+            log.error(m.name())
+        else:
+            m = ctx.load_module(f)
+            if m is not None:
+                log.info("module: {} is loaded successfully".format(m.name()))
+
+    try:
+        root = ctx.parse_data_path(yangDataInst, ly.LYD_JSON, ly.LYD_OPT_CONFIG | ly.LYD_OPT_STRICT)
+        
+        if root:
+            log.info("Tree DFS\n")
+            p = root.print_mem(ly.LYD_JSON, ly.LYP_WITHSIBLINGS | ly.LYP_FORMAT)
+            log.info("===================Data=================")
+            log.info(p)
+
+            sYangInst = sy.sonic_yang(yangDir)
+            sYangInst.root = root
+            sYangInst.validate_data_tree(root, ctx)
+
+            xpath = "/sonic-port:PORT/PORT_LIST[port_name='Ethernet1']/port_name"
+            #find_topo_sort_dependencies(sYangInst, xpath)
+            refs = sYangInst.find_data_dependencies(xpath)
+            printList(refs)
+
+    except Exception as e:
+        print(e)
+
+
+def printList(l): # list l
+
+    print("list: ")
+    for item in l:
+        print (item)
+    
+    return
+
+if __name__ == '__main__':
+    main()
\ No newline at end of file
diff --git a/src/sonic-yang-mgmt/yang-models/Sonic Yang Tree b/src/sonic-yang-mgmt/yang-models/Sonic Yang Tree
new file mode 100644
index 000000000000..6dc84d264054
--- /dev/null
+++ b/src/sonic-yang-mgmt/yang-models/Sonic Yang Tree	
@@ -0,0 +1,101 @@
+module: sonic-acl
+  +--rw sonic-acl
+     +--rw ACL_RULE
+     |  +--rw ACL_RULE_LIST* [ACL_TABLE_NAME RULE_NAME]
+     |     +--rw ACL_TABLE_NAME             -> /sonic-acl/ACL_TABLE/ACL_TABLE_LIST/ACL_TABLE_NAME
+     |     +--rw RULE_NAME                  string
+     |     +--rw PACKET_ACTION?             head:packet_action
+     |     +--rw IP_TYPE?                   head:ip_type
+     |     +--rw PRIORITY?                  uint32
+     |     +--rw (ip_prefix)?
+     |     |  +--:(ip4_prefix)
+     |     |  |  +--rw SRC_IP?              inet:ipv4-prefix
+     |     |  |  +--rw DST_IP?              inet:ipv4-prefix
+     |     |  +--:(ip6_prefix)
+     |     |     +--rw SRC_IPV6?            inet:ipv6-prefix
+     |     |     +--rw DST_IPV6?            inet:ipv6-prefix
+     |     +--rw IN_PORTS*                  uint16
+     |     +--rw OUT_PORTS*                 uint16
+     |     +--rw (src_port)?
+     |     |  +--:(l4_src_port)
+     |     |  |  +--rw L4_SRC_PORT?         uint16
+     |     |  +--:(l4_src_port_range)
+     |     |     +--rw L4_SRC_PORT_RANGE?   string
+     |     +--rw (dst_port)?
+     |     |  +--:(l4_dst_port)
+     |     |  |  +--rw L4_DST_PORT?         uint16
+     |     |  +--:(l4_dst_port_range)
+     |     |     +--rw L4_DST_PORT_RANGE?   string
+     |     +--rw ETHER_TYPE?                string
+     |     +--rw IP_PROTOCOL?               uint8
+     |     +--rw TCP_FLAGS?                 string
+     |     +--rw DSCP?                      uint8
+     |     +--rw TC?                        uint8
+     |     +--rw (icmp)?
+     |     |  +--:(icmp4)
+     |     |  |  +--rw ICMP_TYPE?           uint8
+     |     |  |  +--rw ICMP_CODE?           uint8
+     |     |  +--:(icmp6)
+     |     |     +--rw ICMPV6_TYPE?         uint8
+     |     |     +--rw ICMPV6_CODE?         uint8
+     |     +--rw INNER_ETHER_TYPE?          string
+     |     +--rw INNER_IP_PROTOCOL?         uint8
+     |     +--rw INNER_L4_SRC_PORT?         uint16
+     |     +--rw INNER_L4_DST_PORT?         uint16
+     +--rw ACL_TABLE
+        +--rw ACL_TABLE_LIST* [ACL_TABLE_NAME]
+           +--rw ACL_TABLE_NAME    string
+           +--rw policy_desc?      string
+           +--rw type?             head:acl_table_type
+           +--rw stage?            enumeration
+           +--rw ports*            union
+module: sonic-interface
+  +--rw sonic-interface
+     +--rw INTERFACE
+        +--rw INTERFACE_LIST* [interface ip-prefix]
+           +--rw interface    -> /port:sonic-port/PORT/PORT_LIST/port_name
+           +--rw ip-prefix    inet:ip-prefix
+           +--rw scope?       enumeration
+           +--rw family?      head:ip-family
+module: sonic-port
+  +--rw sonic-port
+     +--rw PORT
+        +--rw PORT_LIST* [port_name]
+           +--rw port_name       string
+           +--rw alias?          string
+           +--rw lanes?          string
+           +--rw description?    string
+           +--rw speed?          uint32
+           +--rw mtu?            uint16
+           +--rw admin_status    head:admin_status
+module: sonic-portchannel
+  +--rw sonic-portchannel
+     +--rw PORTCHANNEL
+        +--rw PORTCHANNEL_LIST* [portchannel_name]
+           +--rw portchannel_name    string
+           +--rw members*            -> /port:sonic-port/PORT/PORT_LIST/port_name
+           +--rw min_links?          uint8
+           +--rw description?        string
+           +--rw mtu?                uint16
+           +--rw admin_status        head:admin_status
+module: sonic-vlan
+  +--rw sonic-vlan
+     +--rw VLAN_INTERFACE
+     |  +--rw VLAN_INTERFACE_LIST* [vlanid ip-prefix]
+     |     +--rw vlanid       -> ../../../VLAN/VLAN_LIST/vlanid
+     |     +--rw ip-prefix    inet:ip-prefix
+     |     +--rw scope?       enumeration
+     |     +--rw family?      head:ip-family
+     +--rw VLAN
+     |  +--rw VLAN_LIST* [vlanid]
+     |     +--rw vlanid          uint16
+     |     +--rw description?    string
+     |     +--rw dhcp_servers*   inet:ip-address
+     |     +--rw mtu?            uint16
+     |     +--rw admin_status    head:admin_status
+     |     +--rw members*        -> /port:sonic-port/PORT/PORT_LIST/port_name
+     +--rw VLAN_MEMBER
+        +--rw VLAN_MEMBER_LIST* [vlanid port]
+           +--rw vlanid          -> ../../../VLAN/VLAN_LIST/vlanid
+           +--rw port            -> /port:sonic-port/PORT/PORT_LIST/port_name
+           +--rw tagging_mode    head:vlan_tagging_mode
diff --git a/src/sonic-yang-mgmt/yang-models/sonic-acl.yang b/src/sonic-yang-mgmt/yang-models/sonic-acl.yang
new file mode 100644
index 000000000000..cdd5a53f912e
--- /dev/null
+++ b/src/sonic-yang-mgmt/yang-models/sonic-acl.yang
@@ -0,0 +1,272 @@
+module sonic-acl {
+
+	namespace "http://github.com/Azure/sonic-acl";
+	prefix acl;
+
+	import ietf-yang-types {
+		prefix yang;
+	}
+
+	import ietf-inet-types {
+		prefix inet;
+	}
+
+	import sonic-head {
+		prefix head;
+		revision-date 2019-07-01;
+	}
+
+	import sonic-port {
+		prefix port;
+		revision-date 2019-07-01;
+	}
+
+	import sonic-portchannel {
+		prefix lag;
+		revision-date 2019-07-01;
+	}
+
+	organization "Linkedin Corporation";
+
+	contact "lnos_coders@linkedin.com";
+
+	description "ACL YANG Module for SONiC OS";
+
+	revision 2019-07-01 {
+		description "First Revision";
+	}
+
+	container sonic-acl {
+
+		container ACL_RULE {
+
+			description "ACL_RULE part of config_db.json";
+
+			list ACL_RULE_LIST {
+
+				key "ACL_TABLE_NAME RULE_NAME";
+
+				leaf ACL_TABLE_NAME {
+					type leafref {
+						path "/acl:sonic-acl/acl:ACL_TABLE/acl:ACL_TABLE_LIST/acl:ACL_TABLE_NAME";
+					}
+				}
+
+				leaf RULE_NAME {
+					type string {
+						length 1..255;
+					}
+				}
+
+				leaf PACKET_ACTION {
+					type head:packet_action;
+				}
+
+				leaf IP_TYPE {
+					type head:ip_type;
+				}
+
+				leaf PRIORITY {
+					type uint32 {
+						range 0..999999;
+					}
+				}
+
+				choice ip_prefix {
+
+					case ip4_prefix {
+						when "boolean(IP_TYPE[.='ANY' or .='IP' or .='IPV4' or .='IPV4ANY' or .='ARP'])";
+						leaf SRC_IP {
+							type inet:ipv4-prefix;
+						}
+
+						leaf DST_IP {
+							type inet:ipv4-prefix;
+						}
+					}
+
+					case ip6_prefix {
+						when "boolean(IP_TYPE[.='ANY' or .='IP' or .='IPV6' or .='IPV6ANY'])";
+						leaf SRC_IPV6 {
+							type inet:ipv6-prefix;
+						}
+
+						leaf DST_IPV6 {
+							type inet:ipv6-prefix;
+						}
+					}
+				}
+
+				leaf-list IN_PORTS {
+					/* Values in leaf list are UNIQUE */
+					type uint16;
+				}
+
+				leaf-list OUT_PORTS {
+					/* Values in leaf list are UNIQUE */
+					type uint16;
+				}
+
+				choice src_port {
+					case l4_src_port {
+						leaf L4_SRC_PORT {
+							type uint16;
+						}
+					}
+
+					case l4_src_port_range {
+						leaf L4_SRC_PORT_RANGE {
+							type string {
+								pattern '([0-9]{1,4}|[0-5][0-9]{4}|[6][0-4][0-9]{3}|[6][5][0-2][0-9]{2}|[6][5][3][0-5]{2}|[6][5][3][6][0-5])-([0-9]{1,4}|[0-5][0-9]{4}|[6][0-4][0-9]{3}|[6][5][0-2][0-9]{2}|[6][5][3][0-5]{2}|[6][5][3][6][0-5])';
+							}
+						}
+					}
+				}
+
+				choice dst_port {
+					case l4_dst_port {
+						leaf L4_DST_PORT {
+							type uint16;
+						}
+					}
+
+					case l4_dst_port_range {
+						leaf L4_DST_PORT_RANGE {
+							type string {
+								pattern '([0-9]{1,4}|[0-5][0-9]{4}|[6][0-4][0-9]{3}|[6][5][0-2][0-9]{2}|[6][5][3][0-5]{2}|[6][5][3][6][0-5])-([0-9]{1,4}|[0-5][0-9]{4}|[6][0-4][0-9]{3}|[6][5][0-2][0-9]{2}|[6][5][3][0-5]{2}|[6][5][3][6][0-5])';
+							}
+						}
+					}
+				}
+
+				leaf ETHER_TYPE {
+					type string {
+						pattern "(0x88CC|0x8100|0x8915|0x0806|0x0800|0x86DD|0x8847)";
+					}
+				}
+
+				leaf IP_PROTOCOL {
+					type uint8 {
+						range 1..143;
+					}
+				}
+
+				leaf TCP_FLAGS {
+					type string {
+						pattern '0[x][0-9a-fA-F]{1,2}|0[X][0-9a-fA-F]{1,2}';
+					}
+				}
+
+				leaf DSCP {
+					type uint8;
+				}
+
+				leaf TC {
+					type uint8;
+				}
+
+				choice icmp {
+
+					case icmp4 {
+						when "boolean(IP_TYPE[.='ANY' or .='IP' or .='IPV4' or .='IPV4ANY' or .='ARP'])";
+						leaf ICMP_TYPE {
+							type uint8 {
+								range 1..44;
+							}
+						}
+
+						leaf ICMP_CODE {
+							type uint8 {
+								range 1..16;
+							}
+						}
+					}
+
+					case icmp6 {
+						when "boolean(IP_TYPE[.='ANY' or .='IP' or .='IPV6' or .='IPV6ANY'])";
+						leaf ICMPV6_TYPE {
+							type uint8 {
+								range 1..44;
+							}
+						}
+
+						leaf ICMPV6_CODE {
+							type uint8 {
+								range 1..16;
+							}
+						}
+					}
+				}
+
+				leaf INNER_ETHER_TYPE {
+					type string {
+						pattern "(0x88CC|0x8100|0x8915|0x0806|0x0800|0x86DD|0x8847)";
+					}
+				}
+
+				leaf INNER_IP_PROTOCOL {
+					type uint8 {
+						range 1..143;
+					}
+				}
+
+				leaf INNER_L4_SRC_PORT {
+					type uint16;
+				}
+
+				leaf INNER_L4_DST_PORT {
+					type uint16;
+				}
+			}
+			/* end of ACL_RULE_LIST */
+		}
+		/* end of container ACL_RULE */
+
+		container ACL_TABLE {
+
+			description "ACL_TABLE part of config_db.json";
+
+			list ACL_TABLE_LIST {
+
+				key "ACL_TABLE_NAME";
+
+				leaf ACL_TABLE_NAME {
+					type string;
+				}
+
+				leaf policy_desc {
+					type string {
+						length 1..255;
+					}
+				}
+
+				leaf type {
+					type head:acl_table_type;
+				}
+
+				leaf stage {
+					type enumeration {
+						enum INGRESS;
+						enum EGRESS;
+					}
+				}
+
+				leaf-list ports {
+                    /* union of leafref is allowed in YANG 1.1 */
+					type union {
+						type leafref {
+							path /port:sonic-port/port:PORT/port:PORT_LIST/port:port_name;
+						}
+						type leafref {
+							path /lag:sonic-portchannel/lag:PORTCHANNEL/lag:PORTCHANNEL_LIST/lag:portchannel_name;
+						}
+					}
+				}
+			}
+			/* end of ACL_TABLE_LIST */
+		}
+        /* end of container ACL_TABLE */
+	}
+    /* end of container sonic-acl */
+}
+/* end of module sonic-acl */
diff --git a/src/sonic-yang-mgmt/yang-models/sonic-head.yang b/src/sonic-yang-mgmt/yang-models/sonic-head.yang
new file mode 100644
index 000000000000..dd0da92c7152
--- /dev/null
+++ b/src/sonic-yang-mgmt/yang-models/sonic-head.yang
@@ -0,0 +1,72 @@
+module sonic-head {
+
+    namespace "http://sonic-head";
+    prefix sonic-head;
+
+    organization "Linkedin Corporation";
+
+    contact "lnos_coders@linkedin.com";
+
+    description "Head yang Module for SONiC OS";
+    
+    revision 2019-07-01 {
+        description "First Revision";
+    }
+    
+    typedef ip-family {
+        type enumeration {
+            enum IPv4;
+            enum IPv6;
+        }
+    }
+
+    typedef admin_status {
+        type enumeration {
+            enum up;
+            enum down;
+        }
+    }
+
+    typedef packet_action{
+        type enumeration {
+            enum DROP;
+            enum FORWARD;
+            enum REDIRECT;
+        }
+    }
+
+    typedef ip_type {
+        type enumeration {
+            enum ANY;
+            enum IP;
+            enum NON_IP;
+            enum IPV4;
+            enum IPV6;
+            enum IPV4ANY;
+            enum NON_IPv4;
+            enum IPV6ANY;
+            enum NON_IPv6;
+            enum ARP;
+        }
+    }
+
+    typedef acl_table_type {
+        type enumeration {
+            enum L2;
+            enum L3;
+            enum L3V6;
+            enum MIRROR;
+            enum MIRRORV6;
+            enum MIRROR_DSCP;
+            enum CTRLPLANE;
+        }
+    }
+
+    typedef vlan_tagging_mode {
+        type enumeration {
+            enum tagged;
+            enum untagged;
+            enum priority_tagged;
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/sonic-yang-mgmt/yang-models/sonic-interface.yang b/src/sonic-yang-mgmt/yang-models/sonic-interface.yang
new file mode 100644
index 000000000000..dc8bc7389ea1
--- /dev/null
+++ b/src/sonic-yang-mgmt/yang-models/sonic-interface.yang
@@ -0,0 +1,78 @@
+module sonic-interface {
+
+	namespace "http://github.com/Azure/sonic-interface";
+	prefix intf;
+
+	import ietf-yang-types {
+		prefix yang;
+	}
+
+	import ietf-inet-types {
+		prefix inet;
+	}
+
+	import sonic-head {
+		prefix head;
+		revision-date 2019-07-01;
+	}
+
+	import sonic-port {
+		prefix port;
+		revision-date 2019-07-01;
+	}
+
+	organization "Linkedin Corporation";
+
+	contact "lnos_coders@linkedin.com";
+
+	description "INTERFACE yang Module for SONiC OS";
+
+	revision 2019-07-01 {
+		description "First Revision";
+	}
+
+	container sonic-interface {
+		container INTERFACE {
+
+			description "INTERFACE part of config_db.json";
+
+			list INTERFACE_LIST {
+
+				key "interface ip-prefix";
+
+				leaf interface {
+					type leafref {
+						path /port:sonic-port/port:PORT/port:PORT_LIST/port:port_name;
+					}
+				}
+
+				leaf ip-prefix {
+					type inet:ip-prefix;
+				}
+
+				leaf scope {
+					type enumeration {
+						enum global;
+						enum local;
+					}
+				}
+
+				leaf family {
+
+					/* family leaf needed for backward compatibility
+					   Both ip4 and ip6 address are string in IETF RFC 6021,
+					   so must statement can check based on : or ., family
+					   should be IPv4 or IPv6 according.
+					 */
+
+					must "(contains(../ip-prefix, ':') and current()='IPv6') or
+						(contains(../ip-prefix, '.') and current()='IPv4')";
+					type head:ip-family;
+				}
+			}
+			/* end of INTERFACE_LIST */
+
+		}
+		/* end of INTERFACE container */
+	}
+}
diff --git a/src/sonic-yang-mgmt/yang-models/sonic-port.yang b/src/sonic-yang-mgmt/yang-models/sonic-port.yang
new file mode 100644
index 000000000000..be04a8aea4bd
--- /dev/null
+++ b/src/sonic-yang-mgmt/yang-models/sonic-port.yang
@@ -0,0 +1,84 @@
+module sonic-port{
+
+	namespace "http://github.com/Azure/sonic-port";
+	prefix port;
+
+	import ietf-yang-types {
+		prefix yang;
+	}
+
+	import ietf-inet-types {
+		prefix inet;
+	}
+
+	import sonic-head {
+		prefix head;
+		revision-date 2019-07-01;
+	}
+
+	organization "Linkedin Corporation";
+
+	contact "lnos_coders@linkedin.com";
+
+	description "PORT yang Module for SONiC OS";
+
+	revision 2019-07-01 {
+		description "First Revision";
+	}
+
+	container sonic-port{
+		container PORT {
+
+			description "PORT part of config_db.json";
+
+			list PORT_LIST {
+
+				key "port_name";
+
+				leaf port_name {
+					type string {
+						length 1..128;
+					}
+				}
+
+				leaf alias {
+					type string {
+						length 1..128;
+					}
+				}
+
+				leaf lanes {
+					type string {
+						length 1..128;
+					}
+				}
+
+				leaf description {
+					type string {
+						length 1..255;
+					}
+				}
+
+				leaf speed {
+					type uint32 {
+						range 1..100000;
+					}
+				}
+
+				leaf mtu {
+					type uint16 {
+						range 1..9216;
+					}
+				}
+
+				leaf admin_status {
+					mandatory true;
+					type head:admin_status;
+				}
+			} /* end of list PORT_LIST */
+
+		} /* end of container PORT */
+
+	} /* end of container sonic-port */
+
+} /* end of module sonic-port */
diff --git a/src/sonic-yang-mgmt/yang-models/sonic-portchannel.yang b/src/sonic-yang-mgmt/yang-models/sonic-portchannel.yang
new file mode 100644
index 000000000000..656351f4e635
--- /dev/null
+++ b/src/sonic-yang-mgmt/yang-models/sonic-portchannel.yang
@@ -0,0 +1,85 @@
+module sonic-portchannel {
+
+	namespace "http://github.com/Azure/sonic-portchannel";
+	prefix lag;
+
+	import ietf-yang-types {
+		prefix yang;
+	}
+
+	import ietf-inet-types {
+		prefix inet;
+	}
+
+	import sonic-head {
+		prefix head;
+		revision-date 2019-07-01;
+	}
+
+	import sonic-port {
+		prefix port;
+		revision-date 2019-07-01;
+	}
+
+	organization "Linkedin Corporation";
+
+	contact "lnos_coders@linkedin.com";
+
+	description "PORTCHANNEL yang Module for SONiC OS";
+
+	revision 2019-07-01 {
+		description "First Revision";
+	}
+
+	container sonic-portchannel {
+		container PORTCHANNEL {
+
+			description "PORTCHANNEL part of config_db.json";
+
+			list PORTCHANNEL_LIST {
+
+				key "portchannel_name";
+
+				leaf portchannel_name {
+					type string {
+						length 1..128;
+						pattern 'PortChannel[0-9]{1,4}';
+					}
+				}
+
+				leaf-list members {
+					/* leaf-list members are unique by default */
+					type leafref {
+						path /port:sonic-port/port:PORT/port:PORT_LIST/port:port_name;
+					}
+				}
+
+				leaf min_links {
+					type uint8 {
+						range 1..128;
+					}
+				}
+
+				leaf description {
+					type string {
+						length 1..255;
+					}
+				}
+
+				leaf mtu {
+					type uint16 {
+						range 1..9216;
+					}
+				}
+
+				leaf admin_status {
+					mandatory true;
+					type head:admin_status;
+				}
+			} /* end of list PORTCHANNEL_LIST */
+
+		} /* end of container PORTCHANNEL */
+
+	} /* end of container sonic-portchannel */
+
+} /* end of module sonic-port */
diff --git a/src/sonic-yang-mgmt/yang-models/sonic-vlan.yang b/src/sonic-yang-mgmt/yang-models/sonic-vlan.yang
new file mode 100644
index 000000000000..6058ce3f1bfc
--- /dev/null
+++ b/src/sonic-yang-mgmt/yang-models/sonic-vlan.yang
@@ -0,0 +1,158 @@
+module sonic-vlan {
+
+	namespace "http://github.com/Azure/sonic-vlan";
+	prefix vlan;
+
+	import ietf-yang-types {
+		prefix yang;
+	}
+
+	import ietf-inet-types {
+		prefix inet;
+	}
+
+	import sonic-head {
+		prefix head;
+		revision-date 2019-07-01;
+	}
+
+	import sonic-port {
+		prefix port;
+		revision-date 2019-07-01;
+	}
+
+	organization "Linkedin Corporation";
+
+	contact "lnos_coders@linkedin.com";
+
+	description "VLAN yang Module for SONiC OS";
+
+	revision 2019-07-01 {
+		description "First Revision";
+	}
+
+	container sonic-vlan {
+		container VLAN_INTERFACE {
+
+			description "VLAN_INTERFACE part of config_db.json";
+
+			list VLAN_INTERFACE_LIST {
+
+				key "vlanid ip-prefix";
+
+				leaf vlanid {
+					type leafref {
+						path ../../../VLAN/VLAN_LIST/vlanid;
+					}
+				}
+
+				leaf ip-prefix {
+					mandatory true;
+					type inet:ip-prefix;
+				}
+
+				leaf scope {
+					type enumeration {
+						enum global;
+						enum local;
+					}
+				}
+
+				leaf family {
+
+					/* family leaf needed for backward compatibility
+					   Both ip4 and ip6 address are string in IETF RFC 6021,
+					   so must statement can check based on : or ., family
+					   should be IPv4 or IPv6 according.
+					 */
+
+					must "(contains(../ip-prefix, ':') and current()='IPv6') or
+						(contains(../ip-prefix, '.') and current()='IPv4')";
+					type head:ip-family;
+				}
+			}
+			/* end of VLAN_INTERFACE_LIST */
+		}
+		/* end of VLAN_INTERFACE container */
+
+		container VLAN {
+
+			description "VLAN part of config_db.json";
+
+			list VLAN_LIST {
+
+				key "vlanid";
+
+				leaf vlanid {
+					type uint16 {
+						range 1..4094;
+					}
+				}
+
+				leaf description {
+					type string {
+						length 1..255;
+					}
+				}
+
+				leaf-list dhcp_servers {
+					type inet:ip-address;
+				}
+
+				leaf mtu {
+					type uint16 {
+						range 1..9216;
+					}
+				}
+
+				leaf admin_status {
+					mandatory true;
+					type head:admin_status;
+				}
+
+				leaf-list members {
+					/* leaf-list members are unique by default */
+
+					type leafref {
+						path /port:sonic-port/port:PORT/port:PORT_LIST/port:port_name;
+					}
+				}
+			}
+			/* end of VLAN_LIST */
+		}
+		/* end of container VLAN */
+
+		container VLAN_MEMBER {
+
+			description "VLAN_MEMBER part of config_db.json";
+
+			list VLAN_MEMBER_LIST {
+
+				key "vlanid port";
+
+				leaf vlanid {
+					type leafref {
+						path ../../../VLAN/VLAN_LIST/vlanid;
+					}
+				}
+
+				leaf port {
+					/* key elements are mandatory by default */
+					mandatory true;
+					type leafref {
+						path /port:sonic-port/port:PORT/port:PORT_LIST/port:port_name;
+					}
+				}
+
+				leaf tagging_mode {
+					mandatory true;
+					type head:vlan_tagging_mode;
+				}
+			}
+            /* end of list VLAN_MEMBER_LIST */
+		}
+        /* end of container VLAN_MEMBER */
+	}
+    /* end of container sonic-vlan */
+}
+/* end of module sonic-vlan */