diff --git a/cfgmgr/Makefile.am b/cfgmgr/Makefile.am
index dcd652498c51..21b1a5f91f0c 100644
--- a/cfgmgr/Makefile.am
+++ b/cfgmgr/Makefile.am
@@ -38,7 +38,7 @@ portmgrd_CFLAGS = $(DBGFLAGS) $(AM_CFLAGS) $(CFLAGS_COMMON) $(CFLAGS_SAI)
 portmgrd_CPPFLAGS = $(DBGFLAGS) $(AM_CFLAGS) $(CFLAGS_COMMON) $(CFLAGS_SAI)
 portmgrd_LDADD = $(COMMON_LIBS) $(SAIMETA_LIBS)
 
-intfmgrd_SOURCES = intfmgrd.cpp intfmgr.cpp $(top_srcdir)/orchagent/orch.cpp $(top_srcdir)/orchagent/request_parser.cpp shellcmd.h
+intfmgrd_SOURCES = intfmgrd.cpp intfmgr.cpp $(top_srcdir)/orchagent/orch.cpp $(top_srcdir)/orchagent/request_parser.cpp $(top_srcdir)/lib/subintf.cpp shellcmd.h
 intfmgrd_CFLAGS = $(DBGFLAGS) $(AM_CFLAGS) $(CFLAGS_COMMON) $(CFLAGS_SAI)
 intfmgrd_CPPFLAGS = $(DBGFLAGS) $(AM_CFLAGS) $(CFLAGS_COMMON) $(CFLAGS_SAI)
 intfmgrd_LDADD = $(COMMON_LIBS) $(SAIMETA_LIBS)
diff --git a/cfgmgr/intfmgr.cpp b/cfgmgr/intfmgr.cpp
index d0eaca21d93d..1567762ffaca 100644
--- a/cfgmgr/intfmgr.cpp
+++ b/cfgmgr/intfmgr.cpp
@@ -9,13 +9,16 @@
 #include "shellcmd.h"
 #include "macaddress.h"
 #include "warm_restart.h"
+#include "subscriberstatetable.h"
 #include <swss/redisutility.h>
+#include "subintf.h"
 
 using namespace std;
 using namespace swss;
 
 #define VLAN_PREFIX         "Vlan"
 #define LAG_PREFIX          "PortChannel"
+#define SUBINTF_LAG_PREFIX  "Po"
 #define LOOPBACK_PREFIX     "Loopback"
 #define VNET_PREFIX         "Vnet"
 #define MTU_INHERITANCE     "0"
@@ -23,6 +26,7 @@ using namespace swss;
 #define VRF_MGMT            "mgmt"
 
 #define LOOPBACK_DEFAULT_MTU_STR "65536"
+#define DEFAULT_MTU_STR 9100
 
 IntfMgr::IntfMgr(DBConnector *cfgDb, DBConnector *appDb, DBConnector *stateDb, const vector<string> &tableNames) :
         Orch(cfgDb, tableNames),
@@ -35,8 +39,19 @@ IntfMgr::IntfMgr(DBConnector *cfgDb, DBConnector *appDb, DBConnector *stateDb, c
         m_stateVlanTable(stateDb, STATE_VLAN_TABLE_NAME),
         m_stateVrfTable(stateDb, STATE_VRF_TABLE_NAME),
         m_stateIntfTable(stateDb, STATE_INTERFACE_TABLE_NAME),
-        m_appIntfTableProducer(appDb, APP_INTF_TABLE_NAME)
+        m_appIntfTableProducer(appDb, APP_INTF_TABLE_NAME),
+        m_appLagTable(appDb, APP_LAG_TABLE_NAME)
 {
+    auto subscriberStateTable = new swss::SubscriberStateTable(stateDb,
+            STATE_PORT_TABLE_NAME, TableConsumable::DEFAULT_POP_BATCH_SIZE, 100);
+    auto stateConsumer = new Consumer(subscriberStateTable, this, STATE_PORT_TABLE_NAME);
+    Orch::addExecutor(stateConsumer);
+
+    auto subscriberStateLagTable = new swss::SubscriberStateTable(stateDb,
+            STATE_LAG_TABLE_NAME, TableConsumable::DEFAULT_POP_BATCH_SIZE, 200);
+    auto stateLagConsumer = new Consumer(subscriberStateLagTable, this, STATE_LAG_TABLE_NAME);
+    Orch::addExecutor(stateLagConsumer);
+
     if (!WarmStart::isWarmStart())
     {
         flushLoopbackIntfs();
@@ -288,22 +303,160 @@ void IntfMgr::addHostSubIntf(const string&intf, const string &subIntf, const str
     EXEC_WITH_ERROR_THROW(cmd.str(), res);
 }
 
-void IntfMgr::setHostSubIntfMtu(const string &subIntf, const string &mtu)
+
+std::string IntfMgr::getIntfAdminStatus(const string &alias)
+{
+    Table *portTable;
+    string admin = "down";
+    if (!alias.compare(0, strlen("Eth"), "Eth"))
+    {
+        portTable = &m_statePortTable;
+    }
+    else if (!alias.compare(0, strlen("Po"), "Po"))
+    {
+        portTable = &m_appLagTable;
+    }
+    else
+    {
+        return admin;
+    }
+
+    vector<FieldValueTuple> temp;
+    portTable->get(alias, temp);
+
+    for (auto idx : temp)
+    {
+        const auto &field = fvField(idx);
+        const auto &value = fvValue(idx);
+        if (field == "admin_status")
+        {
+            admin = value;
+        }
+    }
+    return admin;
+}
+
+std::string IntfMgr::getIntfMtu(const string &alias)
+{
+    Table *portTable;
+    string mtu = "0";
+    if (!alias.compare(0, strlen("Eth"), "Eth"))
+    {
+        portTable = &m_statePortTable;
+    }
+    else if (!alias.compare(0, strlen("Po"), "Po"))
+    {
+        portTable = &m_appLagTable;
+    }
+    else
+    {
+        return mtu;
+    }
+    vector<FieldValueTuple> temp;
+    portTable->get(alias, temp);
+    for (auto idx : temp)
+    {
+        const auto &field = fvField(idx);
+        const auto &value = fvValue(idx);
+        if (field == "mtu")
+        {
+            mtu = value;
+        }
+    }
+    if (mtu.empty())
+    {
+        mtu = std::to_string(DEFAULT_MTU_STR);
+    }
+    return mtu;
+}
+
+void IntfMgr::updateSubIntfMtu(const string &alias, const string &mtu)
+{
+    string intf;
+    for (auto entry : m_subIntfList)
+    {
+        intf = entry.first;
+        subIntf subIf(intf);
+        if (subIf.parentIntf() == alias)
+        {
+            std::vector<FieldValueTuple> fvVector;
+
+            string subif_config_mtu = m_subIntfList[intf].mtu;
+            if (subif_config_mtu == MTU_INHERITANCE || subif_config_mtu.empty())
+                subif_config_mtu = std::to_string(DEFAULT_MTU_STR);
+
+            string subintf_mtu = setHostSubIntfMtu(intf, subif_config_mtu, mtu);
+
+            FieldValueTuple fvTuple("mtu", subintf_mtu);
+            fvVector.push_back(fvTuple);
+            m_appIntfTableProducer.set(intf, fvVector);
+        }
+    }
+}
+
+std::string IntfMgr::setHostSubIntfMtu(const string &alias, const string &mtu, const string &parent_mtu)
 {
     stringstream cmd;
     string res;
 
-    cmd << IP_CMD " link set " << shellquote(subIntf) << " mtu " << shellquote(mtu);
+    string subifMtu = mtu;
+    subIntf subIf(alias);
+
+    int pmtu = (uint32_t)stoul(parent_mtu);
+    int cmtu = (uint32_t)stoul(mtu);
+
+    if (pmtu < cmtu)
+    {
+        subifMtu = parent_mtu;
+    }
+    SWSS_LOG_INFO("subintf %s active mtu: %s", alias.c_str(), subifMtu.c_str());
+    cmd << IP_CMD " link set " << shellquote(alias) << " mtu " << shellquote(subifMtu);
     EXEC_WITH_ERROR_THROW(cmd.str(), res);
+
+    return subifMtu;
 }
 
-void IntfMgr::setHostSubIntfAdminStatus(const string &subIntf, const string &adminStatus)
+void IntfMgr::updateSubIntfAdminStatus(const string &alias, const string &admin)
+{
+    string intf;
+    for (auto entry : m_subIntfList)
+    {
+        intf = entry.first;
+        subIntf subIf(intf);
+        if (subIf.parentIntf() == alias)
+        {
+            /*  Avoid duplicate interface admin UP event. */
+            string curr_admin = m_subIntfList[intf].currAdminStatus;
+            if (curr_admin == "up" && curr_admin == admin)
+            {
+                continue;
+            }
+            std::vector<FieldValueTuple> fvVector;
+            string subintf_admin = setHostSubIntfAdminStatus(intf, m_subIntfList[intf].adminStatus, admin); 
+            m_subIntfList[intf].currAdminStatus = subintf_admin;
+            FieldValueTuple fvTuple("admin_status", subintf_admin);
+            fvVector.push_back(fvTuple);
+            m_appIntfTableProducer.set(intf, fvVector);
+        }
+    }
+}
+
+std::string IntfMgr::setHostSubIntfAdminStatus(const string &alias, const string &admin_status, const string &parent_admin_status)
 {
     stringstream cmd;
     string res;
 
-    cmd << IP_CMD " link set " << shellquote(subIntf) << " " << shellquote(adminStatus);
-    EXEC_WITH_ERROR_THROW(cmd.str(), res);
+    if (parent_admin_status == "up" || admin_status == "down")
+    {
+        SWSS_LOG_INFO("subintf %s admin_status: %s", alias.c_str(), admin_status.c_str());
+        cmd << IP_CMD " link set " << shellquote(alias) << " " << shellquote(admin_status);
+        EXEC_WITH_ERROR_THROW(cmd.str(), res);
+        return admin_status;
+    }
+    else
+    {
+        return "down";
+    }
 }
 
 void IntfMgr::removeHostSubIntf(const string &subIntf)
@@ -319,7 +472,7 @@ void IntfMgr::setSubIntfStateOk(const string &alias)
 {
     vector<FieldValueTuple> fvTuples = {{"state", "ok"}};
 
-    if (!alias.compare(0, strlen(LAG_PREFIX), LAG_PREFIX))
+    if (!alias.compare(0, strlen(SUBINTF_LAG_PREFIX), SUBINTF_LAG_PREFIX))
     {
         m_stateLagTable.set(alias, fvTuples);
     }
@@ -332,7 +485,7 @@ void IntfMgr::setSubIntfStateOk(const string &alias)
 
 void IntfMgr::removeSubIntfState(const string &alias)
 {
-    if (!alias.compare(0, strlen(LAG_PREFIX), LAG_PREFIX))
+    if (!alias.compare(0, strlen(SUBINTF_LAG_PREFIX), SUBINTF_LAG_PREFIX))
     {
         m_stateLagTable.del(alias);
     }
@@ -451,6 +604,14 @@ bool IntfMgr::isIntfStateOk(const string &alias)
     {
         return true;
     }
+    else if (!alias.compare(0, strlen(SUBINTF_LAG_PREFIX), SUBINTF_LAG_PREFIX))
+    {
+        if (m_stateLagTable.get(alias, temp))
+        {
+            SWSS_LOG_DEBUG("Lag %s is ready", alias.c_str());
+            return true;
+        }
+    }
 
     return false;
 }
@@ -467,11 +628,24 @@ bool IntfMgr::doIntfGeneralTask(const vector<string>& keys,
     size_t found = alias.find(VLAN_SUB_INTERFACE_SEPARATOR);
     if (found != string::npos)
     {
-        // This is a sub interface
+        subIntf subIf(alias);
         // alias holds the complete sub interface name
         // while parentAlias holds the parent port name
-        vlanId = alias.substr(found + 1);
-        parentAlias = alias.substr(0, found);
+        /*Check if subinterface is valid and sub interface name length is < 15(IFNAMSIZ)*/
+        if (!subIf.isValid())
+        {
+            SWSS_LOG_ERROR("Invalid subnitf: %s", alias.c_str());
+            return true;
+        }
+        parentAlias = subIf.parentIntf();
+        int subIntfId = subIf.subIntfIdx();
+        /*If long name format, subinterface Id is vlanid */
+        if (!subIf.isShortName())
+        {
+            vlanId = std::to_string(subIntfId);
+            FieldValueTuple vlanTuple("vlan", vlanId);
+            data.push_back(vlanTuple);
+        }
     }
     bool is_lo = !alias.compare(0, strlen(LOOPBACK_PREFIX), LOOPBACK_PREFIX);
     string mac = "";
@@ -521,6 +695,10 @@ bool IntfMgr::doIntfGeneralTask(const vector<string>& keys,
         {
             ipv6_link_local_mode = value;
         }
+        else if (field == "vlan")
+        {
+            vlanId = value;
+        }
     }
 
     if (op == SET_COMMAND)
@@ -584,8 +762,14 @@ bool IntfMgr::doIntfGeneralTask(const vector<string>& keys,
 
         if (!parentAlias.empty())
         {
+            subIntf subIf(alias);
             if (m_subIntfList.find(alias) == m_subIntfList.end())
             {
+                if (vlanId == "0" || vlanId.empty())
+                {
+                    SWSS_LOG_INFO("Vlan ID not configured for sub interface %s", alias.c_str());
+                    return false;
+                }
                 try
                 {
                     addHostSubIntf(parentAlias, alias, vlanId);
@@ -596,25 +780,33 @@ bool IntfMgr::doIntfGeneralTask(const vector<string>& keys,
                     return false;
                 }
 
-                m_subIntfList.insert(alias);
+                m_subIntfList[alias].vlanId = vlanId;
             }
 
             if (!mtu.empty())
             {
+                string subintf_mtu;
                 try
                 {
-                    setHostSubIntfMtu(alias, mtu);
+                    string parentMtu = getIntfMtu(subIf.parentIntf());
+                    subintf_mtu = setHostSubIntfMtu(alias, mtu, parentMtu);
+                    FieldValueTuple fvTuple("mtu", mtu);
+                    std::remove(data.begin(), data.end(), fvTuple);
+                    FieldValueTuple newMtuFvTuple("mtu", subintf_mtu);
+                    data.push_back(newMtuFvTuple);
                 }
                 catch (const std::runtime_error &e)
                 {
                     SWSS_LOG_NOTICE("Sub interface ip link set mtu failure. Runtime error: %s", e.what());
                     return false;
                 }
+                m_subIntfList[alias].mtu = mtu;
             }
             else
             {
                 FieldValueTuple fvTuple("mtu", MTU_INHERITANCE);
                 data.push_back(fvTuple);
+                m_subIntfList[alias].mtu = MTU_INHERITANCE;
             }
 
             if (adminStatus.empty())
@@ -625,13 +817,20 @@ bool IntfMgr::doIntfGeneralTask(const vector<string>& keys,
             }
             try
             {
-                setHostSubIntfAdminStatus(alias, adminStatus);
+                string parentAdmin = getIntfAdminStatus(subIf.parentIntf());
+                string subintf_admin = setHostSubIntfAdminStatus(alias, adminStatus, parentAdmin);
+                m_subIntfList[alias].currAdminStatus = subintf_admin;
+                FieldValueTuple fvTuple("admin_status", adminStatus);
+                std::remove(data.begin(), data.end(), fvTuple);
+                FieldValueTuple newAdminFvTuple("admin_status", subintf_admin);
+                data.push_back(newAdminFvTuple);
             }
             catch (const std::runtime_error &e)
             {
                 SWSS_LOG_NOTICE("Sub interface ip link set admin status %s failure. Runtime error: %s", adminStatus.c_str(), e.what());
                 return false;
             }
+            m_subIntfList[alias].adminStatus = adminStatus;
 
             // set STATE_DB port state
             setSubIntfStateOk(alias);
@@ -788,51 +987,57 @@ void IntfMgr::doTask(Consumer &consumer)
     while (it != consumer.m_toSync.end())
     {
         KeyOpFieldsValuesTuple t = it->second;
-
-        vector<string> keys = tokenize(kfvKey(t), config_db_key_delimiter);
-        const vector<FieldValueTuple>& data = kfvFieldsValues(t);
-        string op = kfvOp(t);
-
-        if (keys.size() == 1)
+        if ((table_name == STATE_PORT_TABLE_NAME) || (table_name == STATE_LAG_TABLE_NAME))
         {
-            if((table_name == CFG_VOQ_INBAND_INTERFACE_TABLE_NAME) &&
-                    (op == SET_COMMAND))
-            {
-                //No further processing needed. Just relay to orchagent
-                m_appIntfTableProducer.set(keys[0], data);
-                m_stateIntfTable.hset(keys[0], "vrf", "");
+            doPortTableTask(kfvKey(t), kfvFieldsValues(t), kfvOp(t));
+        }
+        else
+        {
+            vector<string> keys = tokenize(kfvKey(t), config_db_key_delimiter);
+            const vector<FieldValueTuple>& data = kfvFieldsValues(t);
+            string op = kfvOp(t);
 
-                it = consumer.m_toSync.erase(it);
-                continue;
-            }
-            if (!doIntfGeneralTask(keys, data, op))
-            {
-                it++;
-                continue;
-            }
-            else
+            if (keys.size() == 1)
             {
-                //Entry programmed, remove it from pending list if present
-                m_pendingReplayIntfList.erase(keys[0]);
+                if((table_name == CFG_VOQ_INBAND_INTERFACE_TABLE_NAME) &&
+                        (op == SET_COMMAND))
+                {
+                    //No further processing needed. Just relay to orchagent
+                    m_appIntfTableProducer.set(keys[0], data);
+                    m_stateIntfTable.hset(keys[0], "vrf", "");
+
+                    it = consumer.m_toSync.erase(it);
+                    continue;
+                }
+                if (!doIntfGeneralTask(keys, data, op))
+                {
+                    it++;
+                    continue;
+                }
+                else
+                {
+                    //Entry programmed, remove it from pending list if present
+                    m_pendingReplayIntfList.erase(keys[0]);
+                }
             }
-        }
-        else if (keys.size() == 2)
-        {
-            if (!doIntfAddrTask(keys, data, op))
+            else if (keys.size() == 2)
             {
-                it++;
-                continue;
+                if (!doIntfAddrTask(keys, data, op))
+                {
+                    it++;
+                    continue;
+                }
+                else
+                {
+                    //Entry programmed, remove it from pending list if present
+                    m_pendingReplayIntfList.erase(keys[0] + config_db_key_delimiter + keys[1] );
+                }
             }
             else
             {
-                //Entry programmed, remove it from pending list if present
-                m_pendingReplayIntfList.erase(keys[0] + config_db_key_delimiter + keys[1] );
+                SWSS_LOG_ERROR("Invalid key %s", kfvKey(t).c_str());
             }
         }
-        else
-        {
-            SWSS_LOG_ERROR("Invalid key %s", kfvKey(t).c_str());
-        }
 
         it = consumer.m_toSync.erase(it);
     }
@@ -842,3 +1047,26 @@ void IntfMgr::doTask(Consumer &consumer)
         setWarmReplayDoneState();
     }
 }
+
+void IntfMgr::doPortTableTask(const string& key, vector<FieldValueTuple> data, string op)
+{
+    if (op == SET_COMMAND)
+    {
+        for (auto idx : data)
+        {
+            const auto &field = fvField(idx);
+            const auto &value = fvValue(idx);
+
+            if (field == "admin_status")
+            {
+                SWSS_LOG_INFO("Port %s Admin %s", key.c_str(), value.c_str());
+                updateSubIntfAdminStatus(key, value);
+            }
+            else if (field == "mtu")
+            {
+                SWSS_LOG_INFO("Port %s MTU %s", key.c_str(), value.c_str());
+                updateSubIntfMtu(key, value);
+            }
+        }
+    }
+}
diff --git a/cfgmgr/intfmgr.h b/cfgmgr/intfmgr.h
index 655fb4deeb62..e1a5049fff88 100644
--- a/cfgmgr/intfmgr.h
+++ b/cfgmgr/intfmgr.h
@@ -9,6 +9,16 @@
 #include <string>
 #include <set>
 
+struct SubIntfInfo
+{
+    std::string vlanId;
+    std::string mtu;
+    std::string adminStatus;
+    std::string currAdminStatus;
+};
+
+typedef std::map<std::string, SubIntfInfo>             SubIntfMap;
+
 namespace swss {
 
 class IntfMgr : public Orch
@@ -20,9 +30,9 @@ class IntfMgr : public Orch
 private:
     ProducerStateTable m_appIntfTableProducer;
     Table m_cfgIntfTable, m_cfgVlanIntfTable, m_cfgLagIntfTable, m_cfgLoopbackIntfTable;
-    Table m_statePortTable, m_stateLagTable, m_stateVlanTable, m_stateVrfTable, m_stateIntfTable;
+    Table m_statePortTable, m_stateLagTable, m_stateVlanTable, m_stateVrfTable, m_stateIntfTable, m_appLagTable;
 
-    std::set<std::string> m_subIntfList;
+    SubIntfMap m_subIntfList;
     std::set<std::string> m_loopbackIntfList;
     std::set<std::string> m_pendingReplayIntfList;
 
@@ -34,6 +44,7 @@ class IntfMgr : public Orch
     bool doIntfGeneralTask(const std::vector<std::string>& keys, std::vector<FieldValueTuple> data, const std::string& op);
     bool doIntfAddrTask(const std::vector<std::string>& keys, const std::vector<FieldValueTuple>& data, const std::string& op);
     void doTask(Consumer &consumer);
+    void doPortTableTask(const std::string& key, std::vector<FieldValueTuple> data, std::string op);
 
     bool isIntfStateOk(const std::string &alias);
     bool isIntfCreated(const std::string &alias);
@@ -46,9 +57,11 @@ class IntfMgr : public Orch
     void delLoopbackIntf(const std::string &alias);
     void flushLoopbackIntfs(void);
 
+    std::string getIntfAdminStatus(const std::string &alias);
+    std::string getIntfMtu(const std::string &alias);
     void addHostSubIntf(const std::string&intf, const std::string &subIntf, const std::string &vlan);
-    void setHostSubIntfMtu(const std::string &subIntf, const std::string &mtu);
-    void setHostSubIntfAdminStatus(const std::string &subIntf, const std::string &admin_status);
+    std::string setHostSubIntfMtu(const std::string &alias, const std::string &mtu, const std::string &parent_mtu);
+    std::string setHostSubIntfAdminStatus(const std::string &alias, const std::string &admin_status, const std::string &parent_admin_status);
     void removeHostSubIntf(const std::string &subIntf);
     void setSubIntfStateOk(const std::string &alias);
     void removeSubIntfState(const std::string &alias);
@@ -56,6 +69,9 @@ class IntfMgr : public Orch
     bool setIntfProxyArp(const std::string &alias, const std::string &proxy_arp);
     bool setIntfGratArp(const std::string &alias, const std::string &grat_arp);
 
+    void updateSubIntfAdminStatus(const std::string &alias, const std::string &admin);
+    void updateSubIntfMtu(const std::string &alias, const std::string &mtu);
+
     bool m_replayDone {false};
 };
 
diff --git a/orchagent/Makefile.am b/orchagent/Makefile.am
index e0106f00cee4..93d5aa01e040 100644
--- a/orchagent/Makefile.am
+++ b/orchagent/Makefile.am
@@ -38,6 +38,7 @@ endif
 orchagent_SOURCES = \
             main.cpp \
             $(top_srcdir)/lib/gearboxutils.cpp \
+            $(top_srcdir)/lib/subintf.cpp \
             orchdaemon.cpp \
             orch.cpp \
             notifications.cpp \
diff --git a/orchagent/intfsorch.cpp b/orchagent/intfsorch.cpp
index b270a0c5e59e..1feebb4d753e 100644
--- a/orchagent/intfsorch.cpp
+++ b/orchagent/intfsorch.cpp
@@ -657,11 +657,13 @@ void IntfsOrch::doTask(Consumer &consumer)
         MacAddress mac;
 
         uint32_t mtu = 0;
-        bool adminUp = false;
+        bool adminUp;
+        bool adminStateChanged = false;
         uint32_t nat_zone_id = 0;
         string proxy_arp = "";
         string inband_type = "";
         bool mpls = false;
+        string vlan = "";
 
         for (auto idx : data)
         {
@@ -736,6 +738,7 @@ void IntfsOrch::doTask(Consumer &consumer)
                         SWSS_LOG_WARN("Sub interface %s unknown admin status %s", alias.c_str(), value.c_str());
                     }
                 }
+                adminStateChanged = true;
             }
             else if (field == "nat_zone")
             {
@@ -749,6 +752,10 @@ void IntfsOrch::doTask(Consumer &consumer)
             {
                 inband_type = value;
             }
+            else if (field == "vlan")
+            {
+                vlan = value;
+            }
         }
 
         if (alias == "eth0" || alias == "docker0")
@@ -818,7 +825,11 @@ void IntfsOrch::doTask(Consumer &consumer)
             {
                 if (!ip_prefix_in_key && isSubIntf)
                 {
-                    if (!gPortsOrch->addSubPort(port, alias, adminUp, mtu))
+                    if (adminStateChanged == false)
+                    {
+                        adminUp = port.m_admin_state_up;
+                    }
+                    if (!gPortsOrch->addSubPort(port, alias, vlan, adminUp, mtu))
                     {
                         it++;
                         continue;
@@ -858,6 +869,10 @@ void IntfsOrch::doTask(Consumer &consumer)
             }
             else
             {
+                if (adminStateChanged == false)
+                {
+                    adminUp = port.m_admin_state_up;
+                }
                 if (!setIntf(alias, vrf_id, ip_prefix_in_key ? &ip_prefix : nullptr, adminUp, mtu))
                 {
                     it++;
diff --git a/orchagent/portsorch.cpp b/orchagent/portsorch.cpp
index db592024a649..ada1f4bb920b 100755
--- a/orchagent/portsorch.cpp
+++ b/orchagent/portsorch.cpp
@@ -5,6 +5,7 @@
 #include "gearboxutils.h"
 #include "vxlanorch.h"
 #include "directory.h"
+#include "subintf.h"
 
 #include <inttypes.h>
 #include <cassert>
@@ -807,7 +808,7 @@ bool PortsOrch::getPortByBridgePortId(sai_object_id_t bridge_port_id, Port &port
     return false;
 }
 
-bool PortsOrch::addSubPort(Port &port, const string &alias, const bool &adminUp, const uint32_t &mtu)
+bool PortsOrch::addSubPort(Port &port, const string &alias, const string &vlan, const bool &adminUp, const uint32_t &mtu)
 {
     SWSS_LOG_ENTER();
 
@@ -817,21 +818,21 @@ bool PortsOrch::addSubPort(Port &port, const string &alias, const bool &adminUp,
         SWSS_LOG_ERROR("%s is not a sub interface", alias.c_str());
         return false;
     }
-    string parentAlias = alias.substr(0, found);
-    string vlanId = alias.substr(found + 1);
+    subIntf subIf(alias);
+    string parentAlias = subIf.parentIntf();
     sai_vlan_id_t vlan_id;
     try
     {
-        vlan_id = static_cast<sai_vlan_id_t>(stoul(vlanId));
+        vlan_id = static_cast<sai_vlan_id_t>(stoul(vlan));
     }
     catch (const std::invalid_argument &e)
     {
-        SWSS_LOG_ERROR("Invalid argument %s to %s()", vlanId.c_str(), e.what());
+        SWSS_LOG_ERROR("Invalid argument %s to %s()", vlan.c_str(), e.what());
         return false;
     }
     catch (const std::out_of_range &e)
     {
-        SWSS_LOG_ERROR("Out of range argument %s to %s()", vlanId.c_str(), e.what());
+        SWSS_LOG_ERROR("Out of range argument %s to %s()", vlan.c_str(), e.what());
         return false;
     }
     if (vlan_id > MAX_VALID_VLAN_ID)
diff --git a/orchagent/portsorch.h b/orchagent/portsorch.h
index c4e192aa1429..16b4922bc939 100755
--- a/orchagent/portsorch.h
+++ b/orchagent/portsorch.h
@@ -132,7 +132,7 @@ class PortsOrch : public Orch, public Subject
     void refreshPortStatus();
     bool removeAclTableGroup(const Port &p);
 
-    bool addSubPort(Port &port, const string &alias, const bool &adminUp = true, const uint32_t &mtu = 0);
+    bool addSubPort(Port &port, const string &alias, const string &vlan, const bool &adminUp = true, const uint32_t &mtu = 0);
     bool removeSubPort(const string &alias);
     bool updateL3VniStatus(uint16_t vlan_id, bool status);
     void getLagMember(Port &lag, vector<Port> &portv);
diff --git a/portsyncd/linksync.cpp b/portsyncd/linksync.cpp
index 08df3ff9ec6f..4a2b351ee07e 100644
--- a/portsyncd/linksync.cpp
+++ b/portsyncd/linksync.cpp
@@ -182,6 +182,7 @@ void LinkSync::onMsg(int nlmsg_type, struct nl_object *obj)
     unsigned int ifindex = rtnl_link_get_ifindex(link);
     int master = rtnl_link_get_master(link);
     char *type = rtnl_link_get_type(link);
+    unsigned int mtu = rtnl_link_get_mtu(link);
 
     if (type)
     {
@@ -251,10 +252,14 @@ void LinkSync::onMsg(int nlmsg_type, struct nl_object *obj)
     {
         g_portSet.erase(key);
         FieldValueTuple tuple("state", "ok");
+        FieldValueTuple admin_status("admin_status", (admin ? "up" : "down"));
+        FieldValueTuple port_mtu("mtu", to_string(mtu));
         vector<FieldValueTuple> vector;
         vector.push_back(tuple);
         FieldValueTuple op("netdev_oper_status", oper ? "up" : "down");
         vector.push_back(op);
+        vector.push_back(admin_status);
+        vector.push_back(port_mtu);
         m_statePortTable.set(key, vector);
         SWSS_LOG_NOTICE("Publish %s(ok:%s) to state db", key.c_str(), oper ? "up" : "down");
     }
diff --git a/teamsyncd/teamsync.cpp b/teamsyncd/teamsync.cpp
index 846d474a6cd3..6d8c025911b4 100644
--- a/teamsyncd/teamsync.cpp
+++ b/teamsyncd/teamsync.cpp
@@ -157,11 +157,18 @@ void TeamSync::addLag(const string &lagName, int ifindex, bool admin_state,
     SWSS_LOG_INFO("Add %s admin_status:%s oper_status:%s, mtu: %d",
                    lagName.c_str(), admin_state ? "up" : "down", oper_state ? "up" : "down", mtu);
 
+    bool lag_update = true;
     /* Return when the team instance has already been tracked */
     if (m_teamSelectables.find(lagName) != m_teamSelectables.end())
-        return;
+    {
+        auto tsync = m_teamSelectables[lagName];
+        if (tsync->admin_state == admin_state && tsync->mtu == mtu)
+            return;
+        tsync->admin_state = admin_state;
+        tsync->mtu = mtu;
+        lag_update = false;
+    }
 
-    fvVector.clear();
     FieldValueTuple s("state", "ok");
     fvVector.push_back(s);
     if (m_warmstart)
@@ -173,10 +180,13 @@ void TeamSync::addLag(const string &lagName, int ifindex, bool admin_state,
         m_stateLagTable.set(lagName, fvVector);
     }
 
-    /* Create the team instance */
-    auto sync = make_shared<TeamPortSync>(lagName, ifindex, &m_lagMemberTable);
-    m_teamSelectables[lagName] = sync;
-    m_selectablesToAdd.insert(lagName);
+    if (lag_update)
+    {
+        /* Create the team instance */
+        auto sync = make_shared<TeamPortSync>(lagName, ifindex, &m_lagMemberTable);
+        m_teamSelectables[lagName] = sync;
+        m_selectablesToAdd.insert(lagName);
+    }
 }
 
 void TeamSync::removeLag(const string &lagName)
diff --git a/teamsyncd/teamsync.h b/teamsyncd/teamsync.h
index 406953e31210..deb5d8412939 100644
--- a/teamsyncd/teamsync.h
+++ b/teamsyncd/teamsync.h
@@ -43,6 +43,8 @@ class TeamSync : public NetMsg
 
         /* member_name -> enabled|disabled */
         std::map<std::string, bool> m_lagMembers;
+        bool admin_state;
+        unsigned int mtu;
     protected:
         int onChange();
         static int teamdHandler(struct team_handle *th, void *arg,
diff --git a/tests/mock_tests/Makefile.am b/tests/mock_tests/Makefile.am
index 7f31379658f5..741946384784 100644
--- a/tests/mock_tests/Makefile.am
+++ b/tests/mock_tests/Makefile.am
@@ -33,6 +33,7 @@ tests_SOURCES = aclorch_ut.cpp \
                 mock_redisreply.cpp \
                 bulker_ut.cpp \
                 $(top_srcdir)/lib/gearboxutils.cpp \
+                $(top_srcdir)/lib/subintf.cpp \
                 $(top_srcdir)/orchagent/orchdaemon.cpp \
                 $(top_srcdir)/orchagent/orch.cpp \
                 $(top_srcdir)/orchagent/notifications.cpp \
diff --git a/tests/test_sub_port_intf.py b/tests/test_sub_port_intf.py
index 2d442fd027fb..b0f2863aa673 100644
--- a/tests/test_sub_port_intf.py
+++ b/tests/test_sub_port_intf.py
@@ -45,6 +45,7 @@
 PEER_LIST = "peer_list"
 
 ETHERNET_PREFIX = "Ethernet"
+SUBINTF_LAG_PREFIX = "Po"
 LAG_PREFIX = "PortChannel"
 VRF_PREFIX = "Vrf"
 VNET_PREFIX = "Vnet"
@@ -52,6 +53,8 @@
 VLAN_SUB_INTERFACE_SEPARATOR = "."
 APPL_DB_SEPARATOR = ":"
 
+ETHERNET_PORT_DEFAULT_MTU = "1500"
+
 
 class TestSubPortIntf(object):
     SUB_PORT_INTERFACE_UNDER_TEST = "Ethernet64.10"
@@ -97,7 +100,62 @@ def connect_dbs(self, dvs):
             if phy_port in key:
                 self.buf_q_fvs[key] = self.config_db.get_entry("BUFFER_QUEUE", key)
 
+    def get_subintf_longname(self, port_name):
+        if port_name is None:
+            return None
+        sub_intf_sep_idx = port_name.find(VLAN_SUB_INTERFACE_SEPARATOR)
+        if sub_intf_sep_idx == -1:
+            return str(port_name)
+        parent_intf = port_name[:sub_intf_sep_idx]
+        sub_intf_idx = port_name[(sub_intf_sep_idx+1):]
+        if port_name.startswith("Eth"):
+            if port_name.startswith("Ethernet"):
+                intf_index=port_name[len("Ethernet"):sub_intf_sep_idx]
+            else:
+                intf_index=port_name[len("Eth"):sub_intf_sep_idx]
+            return "Ethernet"+intf_index+VLAN_SUB_INTERFACE_SEPARATOR+sub_intf_idx
+        elif port_name.startswith("Po"):
+            if port_name.startswith("PortChannel"):
+                intf_index=port_name[len("PortChannel"):sub_intf_sep_idx]
+            else:
+                intf_index=port_name[len("Po"):sub_intf_sep_idx]
+            return "PortChannel"+intf_index+VLAN_SUB_INTERFACE_SEPARATOR+sub_intf_idx
+        else:
+            return str(port_name)
+   
+    def get_port_longname(self, port_name):
+        if port_name is None:
+           return None
+
+        if VLAN_SUB_INTERFACE_SEPARATOR in port_name:
+           return self.get_subintf_longname(port_name)
+        else:
+            if port_name.startswith("Eth"):
+               if port_name.startswith("Ethernet"):
+                   return port_name
+               intf_index=port_name[len("Eth"):len(port_name)]
+               return "Ethernet"+intf_index
+            elif port_name.startswith("Po"):
+                 if port_name.startswith("PortChannel"):
+                     return port_name
+                 intf_index=port_name[len("Po"):len(port_name)]
+                 return "PortChannel"+intf_index
+            else:
+                 return port_name
+
+    def get_parent_port(self, port_name):
+        port = self.get_port_longname(port_name)
+        idx = port.find(VLAN_SUB_INTERFACE_SEPARATOR)
+        parent_port = ""
+        if port.startswith(ETHERNET_PREFIX):
+            parent_port = port[:idx]
+        else:
+            assert port.startswith(SUBINTF_LAG_PREFIX)
+            parent_port = port[:idx]
+        return parent_port
+
     def get_parent_port_index(self, port_name):
+        port_name = self.get_port_longname(port_name)
         if port_name.startswith(ETHERNET_PREFIX):
             idx = int(port_name[len(ETHERNET_PREFIX):])
         else:
@@ -110,7 +168,7 @@ def set_parent_port_oper_status(self, dvs, port_name, status):
             srv_idx = self.get_parent_port_index(port_name) // 4
             dvs.servers[srv_idx].runcmd("ip link set dev eth0 " + status)
         else:
-            assert port_name.startswith(LAG_PREFIX)
+            assert port_name.startswith(SUBINTF_LAG_PREFIX)
             dvs.runcmd("bash -c 'echo " + ("1" if status == "up" else "0") +
                        " > /sys/class/net/" + port_name + "/carrier'")
         time.sleep(1)
@@ -121,7 +179,7 @@ def set_parent_port_admin_status(self, dvs, port_name, status):
         if port_name.startswith(ETHERNET_PREFIX):
             tbl_name = CFG_PORT_TABLE_NAME
         else:
-            assert port_name.startswith(LAG_PREFIX)
+            assert port_name.startswith(SUBINTF_LAG_PREFIX)
             tbl_name = CFG_LAG_TABLE_NAME
         self.config_db.create_entry(tbl_name, port_name, fvs)
         time.sleep(1)
@@ -154,8 +212,28 @@ def create_vrf(self, vrf_name):
             self.create_vxlan_tunnel(self.TUNNEL_UNDER_TEST, self.VTEP_IP_UNDER_TEST)
             self.create_vnet(vrf_name, self.TUNNEL_UNDER_TEST, self.VNI_UNDER_TEST)
 
+    def is_short_name(self, port_name):
+        idx = port_name.find(VLAN_SUB_INTERFACE_SEPARATOR)
+        parent_port = port_name[:idx]
+        is_short = False
+        if parent_port.startswith("Eth"):
+            if parent_port.startswith(ETHERNET_PREFIX):
+                is_short = False
+            else:
+                is_short = True
+        elif parent_port.startswith("Po"):
+            if parent_port.startswith("PortChannel"):
+                is_short = False
+            else:
+                is_short = True
+        return is_short
+
     def create_sub_port_intf_profile(self, sub_port_intf_name, vrf_name=None):
         fvs = {ADMIN_STATUS: "up"}
+        idx = sub_port_intf_name.find(VLAN_SUB_INTERFACE_SEPARATOR)
+        sub_port_idx = sub_port_intf_name[(idx+1):]
+        if self.is_short_name(sub_port_intf_name) == True:
+            fvs["vlan"] = sub_port_idx
         if vrf_name:
             fvs[VRF_NAME if vrf_name.startswith(VRF_PREFIX) else VNET_NAME] = vrf_name
 
@@ -189,8 +267,12 @@ def add_lag_members(self, lag, members):
             self.config_db.create_entry(CFG_LAG_MEMBER_TABLE_NAME, key, fvs)
 
     def create_sub_port_intf_profile_appl_db(self, sub_port_intf_name, admin_status, vrf_name=None):
+        substrs = sub_port_intf_name.split(VLAN_SUB_INTERFACE_SEPARATOR)
+        parent_port = self.get_parent_port(sub_port_intf_name)
+        vlan_id = substrs[1]
         pairs = [
             (ADMIN_STATUS, admin_status),
+            ("vlan", vlan_id),
             ("mtu", "0"),
         ]
         if vrf_name:
@@ -255,7 +337,7 @@ def remove_parent_port_appl_db(self, port_name):
                 if port_name in key:
                     self.config_db.delete_entry("BUFFER_QUEUE", key)
         else:
-            assert port_name.startswith(LAG_PREFIX)
+            assert port_name.startswith(SUBINTF_LAG_PREFIX)
             tbl_name = APP_LAG_TABLE_NAME
         tbl = swsscommon.ProducerStateTable(self.app_db.db_connection, tbl_name)
         tbl._del(port_name)
@@ -405,14 +487,14 @@ def _access_function():
 
     def _test_sub_port_intf_creation(self, dvs, sub_port_intf_name, vrf_name=None):
         substrs = sub_port_intf_name.split(VLAN_SUB_INTERFACE_SEPARATOR)
-        parent_port = substrs[0]
+        parent_port = self.get_parent_port(sub_port_intf_name)
         vlan_id = substrs[1]
         if parent_port.startswith(ETHERNET_PREFIX):
             state_tbl_name = STATE_PORT_TABLE_NAME
             phy_ports = [parent_port]
             parent_port_oid = dvs.asicdb.portnamemap[parent_port]
         else:
-            assert parent_port.startswith(LAG_PREFIX)
+            assert parent_port.startswith(SUBINTF_LAG_PREFIX)
             state_tbl_name = STATE_LAG_TABLE_NAME
             phy_ports = self.LAG_MEMBERS_UNDER_TEST
             old_lag_oids = self.get_oids(ASIC_LAG_TABLE)
@@ -421,7 +503,7 @@ def _test_sub_port_intf_creation(self, dvs, sub_port_intf_name, vrf_name=None):
         old_rif_oids = self.get_oids(ASIC_RIF_TABLE)
 
         self.set_parent_port_admin_status(dvs, parent_port, "up")
-        if parent_port.startswith(LAG_PREFIX):
+        if parent_port.startswith(SUBINTF_LAG_PREFIX):
             parent_port_oid = self.get_newly_created_oid(ASIC_LAG_TABLE, old_lag_oids)
             # Add lag members to test physical port host interface vlan tag attribute
             self.add_lag_members(parent_port, self.LAG_MEMBERS_UNDER_TEST)
@@ -490,7 +572,7 @@ def _test_sub_port_intf_creation(self, dvs, sub_port_intf_name, vrf_name=None):
                 self.remove_vxlan_tunnel(self.TUNNEL_UNDER_TEST)
                 self.app_db.wait_for_n_keys(ASIC_TUNNEL_TABLE, 0)
 
-        if parent_port.startswith(LAG_PREFIX):
+        if parent_port.startswith(SUBINTF_LAG_PREFIX):
             # Remove lag members from lag parent port
             self.remove_lag_members(parent_port, self.LAG_MEMBERS_UNDER_TEST)
             self.asic_db.wait_for_n_keys(ASIC_LAG_MEMBER_TABLE, 0)
@@ -513,7 +595,7 @@ def test_sub_port_intf_creation(self, dvs):
 
     def _test_sub_port_intf_add_ip_addrs(self, dvs, sub_port_intf_name, vrf_name=None):
         substrs = sub_port_intf_name.split(VLAN_SUB_INTERFACE_SEPARATOR)
-        parent_port = substrs[0]
+        parent_port = self.get_parent_port(sub_port_intf_name)
 
         vrf_oid = self.default_vrf_oid
         old_rif_oids = self.get_oids(ASIC_RIF_TABLE)
@@ -581,7 +663,7 @@ def _test_sub_port_intf_add_ip_addrs(self, dvs, sub_port_intf_name, vrf_name=Non
                 self.app_db.wait_for_n_keys(ASIC_TUNNEL_TABLE, 0)
 
         # Remove lag
-        if parent_port.startswith(LAG_PREFIX):
+        if parent_port.startswith(SUBINTF_LAG_PREFIX):
             self.remove_lag(parent_port)
             self.asic_db.wait_for_n_keys(ASIC_LAG_TABLE, 0)
 
@@ -599,7 +681,7 @@ def test_sub_port_intf_add_ip_addrs(self, dvs):
 
     def _test_sub_port_intf_appl_db_proc_seq(self, dvs, sub_port_intf_name, admin_up, vrf_name=None):
         substrs = sub_port_intf_name.split(VLAN_SUB_INTERFACE_SEPARATOR)
-        parent_port = substrs[0]
+        parent_port = self.get_parent_port(sub_port_intf_name)
         vlan_id = substrs[1]
 
         vrf_oid = self.default_vrf_oid
@@ -610,7 +692,7 @@ def _test_sub_port_intf_appl_db_proc_seq(self, dvs, sub_port_intf_name, admin_up
         if parent_port.startswith(ETHERNET_PREFIX):
             parent_port_oid = dvs.asicdb.portnamemap[parent_port]
         else:
-            assert parent_port.startswith(LAG_PREFIX)
+            assert parent_port.startswith(SUBINTF_LAG_PREFIX)
             parent_port_oid = self.get_newly_created_oid(ASIC_LAG_TABLE, old_lag_oids)
         if vrf_name:
             self.create_vrf(vrf_name)
@@ -656,7 +738,7 @@ def _test_sub_port_intf_appl_db_proc_seq(self, dvs, sub_port_intf_name, admin_up
                 self.app_db.wait_for_n_keys(ASIC_TUNNEL_TABLE, 0)
 
         # Remove lag
-        if parent_port.startswith(LAG_PREFIX):
+        if parent_port.startswith(SUBINTF_LAG_PREFIX):
             self.remove_lag(parent_port)
             self.check_lag_removal(parent_port_oid)
 
@@ -684,6 +766,7 @@ def test_sub_port_intf_appl_db_proc_seq(self, dvs):
     def _test_sub_port_intf_admin_status_change(self, dvs, sub_port_intf_name, vrf_name=None):
         substrs = sub_port_intf_name.split(VLAN_SUB_INTERFACE_SEPARATOR)
         parent_port = substrs[0]
+        parent_port = self.get_parent_port(sub_port_intf_name)
 
         vrf_oid = self.default_vrf_oid
         old_rif_oids = self.get_oids(ASIC_RIF_TABLE)
@@ -779,7 +862,7 @@ def _test_sub_port_intf_admin_status_change(self, dvs, sub_port_intf_name, vrf_n
                 self.app_db.wait_for_n_keys(ASIC_TUNNEL_TABLE, 0)
 
         # Remove lag
-        if parent_port.startswith(LAG_PREFIX):
+        if parent_port.startswith(SUBINTF_LAG_PREFIX):
             self.remove_lag(parent_port)
             self.asic_db.wait_for_n_keys(ASIC_LAG_TABLE, 0)
 
@@ -798,6 +881,7 @@ def test_sub_port_intf_admin_status_change(self, dvs):
     def _test_sub_port_intf_remove_ip_addrs(self, dvs, sub_port_intf_name, vrf_name=None):
         substrs = sub_port_intf_name.split(VLAN_SUB_INTERFACE_SEPARATOR)
         parent_port = substrs[0]
+        parent_port = self.get_parent_port(sub_port_intf_name)
 
         old_rif_oids = self.get_oids(ASIC_RIF_TABLE)
 
@@ -862,7 +946,7 @@ def _test_sub_port_intf_remove_ip_addrs(self, dvs, sub_port_intf_name, vrf_name=
                 self.app_db.wait_for_n_keys(ASIC_TUNNEL_TABLE, 0)
 
         # Remove lag
-        if parent_port.startswith(LAG_PREFIX):
+        if parent_port.startswith(SUBINTF_LAG_PREFIX):
             self.remove_lag(parent_port)
             self.asic_db.wait_for_n_keys(ASIC_LAG_TABLE, 0)
 
@@ -881,6 +965,7 @@ def test_sub_port_intf_remove_ip_addrs(self, dvs):
     def _test_sub_port_intf_removal(self, dvs, sub_port_intf_name, removal_seq_test=False, vrf_name=None):
         substrs = sub_port_intf_name.split(VLAN_SUB_INTERFACE_SEPARATOR)
         parent_port = substrs[0]
+        parent_port = self.get_parent_port(sub_port_intf_name)
         vlan_id = substrs[1]
         if parent_port.startswith(ETHERNET_PREFIX):
             state_tbl_name = STATE_PORT_TABLE_NAME
@@ -888,7 +973,7 @@ def _test_sub_port_intf_removal(self, dvs, sub_port_intf_name, removal_seq_test=
             parent_port_oid = dvs.asicdb.portnamemap[parent_port]
             asic_tbl_name = ASIC_PORT_TABLE
         else:
-            assert parent_port.startswith(LAG_PREFIX)
+            assert parent_port.startswith(SUBINTF_LAG_PREFIX)
             state_tbl_name = STATE_LAG_TABLE_NAME
             phy_ports = self.LAG_MEMBERS_UNDER_TEST
             old_lag_oids = self.get_oids(ASIC_LAG_TABLE)
@@ -898,7 +983,7 @@ def _test_sub_port_intf_removal(self, dvs, sub_port_intf_name, removal_seq_test=
         old_rif_oids = self.get_oids(ASIC_RIF_TABLE)
 
         self.set_parent_port_admin_status(dvs, parent_port, "up")
-        if parent_port.startswith(LAG_PREFIX):
+        if parent_port.startswith(SUBINTF_LAG_PREFIX):
             parent_port_oid = self.get_newly_created_oid(ASIC_LAG_TABLE, old_lag_oids)
             if removal_seq_test == False:
                 # Add lag members to test physical port host interface vlan tag attribute
@@ -981,6 +1066,10 @@ def _test_sub_port_intf_removal(self, dvs, sub_port_intf_name, removal_seq_test=
                 "SAI_ROUTER_INTERFACE_ATTR_PORT_ID": parent_port_oid,
             }
             rif_oid = self.get_newly_created_oid(ASIC_RIF_TABLE, old_rif_oids)
+            #If subintf mtu deleted, it inherits from parent 
+            if vrf_name == self.VRF_UNDER_TEST:
+                if parent_port.startswith(ETHERNET_PREFIX):
+                    fv_dict["SAI_ROUTER_INTERFACE_ATTR_MTU"] = ETHERNET_PORT_DEFAULT_MTU 
             self.check_sub_port_intf_fvs(self.asic_db, ASIC_RIF_TABLE, rif_oid, fv_dict)
         else:
             rif_oid = self.get_newly_created_oid(ASIC_RIF_TABLE, old_rif_oids)
@@ -1076,6 +1165,7 @@ def test_sub_port_intf_removal(self, dvs):
     def _test_sub_port_intf_mtu(self, dvs, sub_port_intf_name, vrf_name=None):
         substrs = sub_port_intf_name.split(VLAN_SUB_INTERFACE_SEPARATOR)
         parent_port = substrs[0]
+        parent_port = self.get_parent_port(sub_port_intf_name)
 
         vrf_oid = self.default_vrf_oid
         old_rif_oids = self.get_oids(ASIC_RIF_TABLE)
@@ -1122,7 +1212,7 @@ def _test_sub_port_intf_mtu(self, dvs, sub_port_intf_name, vrf_name=None):
                 self.app_db.wait_for_n_keys(ASIC_TUNNEL_TABLE, 0)
 
         # Remove lag
-        if parent_port.startswith(LAG_PREFIX):
+        if parent_port.startswith(SUBINTF_LAG_PREFIX):
             self.remove_lag(parent_port)
             self.asic_db.wait_for_n_keys(ASIC_LAG_TABLE, 0)
 
@@ -1244,13 +1334,14 @@ def check_nhg_members_on_parent_port_oper_status_change(self, dvs, parent_port_p
     def _test_sub_port_intf_nhg_accel(self, dvs, sub_port_intf_name, nhop_num=3, create_intf_on_parent_port=False, vrf_name=None):
         substrs = sub_port_intf_name.split(VLAN_SUB_INTERFACE_SEPARATOR)
         parent_port = substrs[0]
+        parent_port = self.get_parent_port(sub_port_intf_name)
         vlan_id = substrs[1]
         assert len(vlan_id) == 2
 
         if parent_port.startswith(ETHERNET_PREFIX):
             parent_port_prefix = ETHERNET_PREFIX
         else:
-            assert parent_port.startswith(LAG_PREFIX)
+            assert parent_port.startswith(SUBINTF_LAG_PREFIX)
             parent_port_prefix = LAG_PREFIX
         parent_port_idx_base = self.get_parent_port_index(parent_port)
 
@@ -1372,13 +1463,14 @@ def _test_sub_port_intf_oper_down_with_pending_neigh_route_tasks(self, dvs, sub_
                                                                      create_intf_on_parent_port=False, vrf_name=None):
         substrs = sub_port_intf_name.split(VLAN_SUB_INTERFACE_SEPARATOR)
         parent_port = substrs[0]
+        parent_port = self.get_parent_port(sub_port_intf_name)
         vlan_id = substrs[1]
         assert len(vlan_id) == 2
 
         if parent_port.startswith(ETHERNET_PREFIX):
             parent_port_prefix = ETHERNET_PREFIX
         else:
-            assert parent_port.startswith(LAG_PREFIX)
+            assert parent_port.startswith(SUBINTF_LAG_PREFIX)
             parent_port_prefix = LAG_PREFIX
         parent_port_idx_base = self.get_parent_port_index(parent_port)