diff --git a/script/check-posix-pty b/script/check-posix-pty
index 5e64783a2..68b57eb9d 100755
--- a/script/check-posix-pty
+++ b/script/check-posix-pty
@@ -129,6 +129,12 @@ send "ipaddr\r\n"
 expect "Done"
 send "coex\r\n"
 expect "Done"
+send "coap start\r\n"
+expect "Done"
+send "coap resource TestResource\r\n"
+expect "Done"
+send "coap set TestContent\r\n"
+expect "Done"
 wait
 EOF
 
@@ -142,7 +148,7 @@ EOF
         fi
     done
 
-    netstat -an | grep -q 61631 || die 'TMF port is not available!'
+    netstat -an | grep -q 5683 || die 'Application CoAP port is not available!'
 
     extaddr=$(grep -aoE '[0-9a-z]{16}' $OT_OUTPUT)
     echo "Extended address is: ${extaddr}"
@@ -157,15 +163,15 @@ EOF
     fi
 
     LEADER_ALOC=fdde:ad00:beef::ff:fe00:fc00
-    # Retrievie extended address through network diagnostic get
-    coap_response=$(echo -n '120100' | xxd -r -p | coap-client -m POST coap://[${LEADER_ALOC}]:61631/d/dg -f- | xxd -p | grep 0008)
+    # Retrievie test resource through application CoAP
+    coap_response=$(coap-client -B 5 -m GET coap://[${LEADER_ALOC}]:5683/TestResource)
     echo "CoAP response is: ${coap_response}"
 
-    # Verify CoAP response contains the extended address
-    if [[ ${coap_response} == *${extaddr}* ]]; then
+    # Verify CoAP response contains the test content
+    if [[ ${coap_response} == *TestContent* ]]; then
         echo 'Success'
     else
-        die 'Failed to get extended address'
+        die 'Failed to access application CoAP'
     fi
 }
 
diff --git a/src/core/net/ip6.cpp b/src/core/net/ip6.cpp
index 93da2099f..053c78300 100644
--- a/src/core/net/ip6.cpp
+++ b/src/core/net/ip6.cpp
@@ -1004,13 +1004,11 @@ otError Ip6::ProcessReceiveCallback(Message &          aMessage,
     if (mIsReceiveIp6FilterEnabled)
     {
         // do not pass messages sent to an RLOC/ALOC, except Service Locator
-#if !OPENTHREAD_CONFIG_PLATFORM_NETIF_ENABLE
         bool isLocator = Get<Mle::Mle>().IsMeshLocalAddress(aMessageInfo.GetSockAddr()) &&
                          aMessageInfo.GetSockAddr().GetIid().IsLocator();
 
         VerifyOrExit(!isLocator || aMessageInfo.GetSockAddr().GetIid().IsAnycastServiceLocator(),
                      error = OT_ERROR_NO_ROUTE);
-#endif
 
         switch (aIpProto)
         {
@@ -1041,13 +1039,11 @@ otError Ip6::ProcessReceiveCallback(Message &          aMessage,
                 // do not pass MLE messages
                 ExitNow(error = OT_ERROR_NO_ROUTE);
             }
-#if !OPENTHREAD_CONFIG_PLATFORM_UDP_ENABLE
             else if ((destPort == Tmf::kUdpPort) && Get<Tmf::TmfAgent>().IsTmfMessage(aMessageInfo))
             {
                 // do not pass TMF messages
                 ExitNow(error = OT_ERROR_NO_ROUTE);
             }
-#endif
 
 #if OPENTHREAD_FTD
             if (destPort == Get<MeshCoP::JoinerRouter>().GetJoinerUdpPort())
diff --git a/src/core/net/udp6.cpp b/src/core/net/udp6.cpp
index 4c579a2bb..af2f9624c 100644
--- a/src/core/net/udp6.cpp
+++ b/src/core/net/udp6.cpp
@@ -242,7 +242,7 @@ otError Udp::Bind(SocketHandle &aSocket, const SockAddr &aSockAddr)
         } while (error != OT_ERROR_NONE);
     }
 #if OPENTHREAD_CONFIG_PLATFORM_UDP_ENABLE
-    else if (!IsMlePort(aSocket.mSockName.mPort))
+    else if (ShouldUsePlatformUdp(aSocket))
     {
         error = otPlatUdpBind(&aSocket);
     }
@@ -275,10 +275,26 @@ void Udp::SetBackboneSocket(SocketHandle &aSocket)
     }
 }
 
-const Udp::SocketHandle *Udp::GetBackboneSockets(void)
+const Udp::SocketHandle *Udp::GetBackboneSockets(void) const
 {
     return mPrevBackboneSockets != nullptr ? mPrevBackboneSockets->GetNext() : mSockets.GetHead();
 }
+
+bool Udp::IsBackboneSocket(const SocketHandle &aSocket) const
+{
+    bool retval = false;
+
+    for (const SocketHandle *sock = GetBackboneSockets(); sock != nullptr; sock = sock->GetNext())
+    {
+        if (sock == &aSocket)
+        {
+            ExitNow(retval = true);
+        }
+    }
+
+exit:
+    return retval;
+}
 #endif
 
 otError Udp::Connect(SocketHandle &aSocket, const SockAddr &aSockAddr)
@@ -293,7 +309,7 @@ otError Udp::Connect(SocketHandle &aSocket, const SockAddr &aSockAddr)
     }
 
 #if OPENTHREAD_CONFIG_PLATFORM_UDP_ENABLE
-    if (!IsMlePort(aSocket.mSockName.mPort))
+    if (ShouldUsePlatformUdp(aSocket))
     {
         error = otPlatUdpConnect(&aSocket);
     }
@@ -356,8 +372,7 @@ otError Udp::SendTo(SocketHandle &aSocket, Message &aMessage, const MessageInfo
     messageInfoLocal.SetSockPort(aSocket.GetSockName().mPort);
 
 #if OPENTHREAD_CONFIG_PLATFORM_UDP_ENABLE
-    if (!IsMlePort(aSocket.mSockName.mPort) &&
-        !(aSocket.mSockName.mPort == Tmf::kUdpPort && aMessage.GetSubType() == Message::kSubTypeJoinerEntrust))
+    if (ShouldUsePlatformUdp(aSocket))
     {
         // Replace anycast address with a valid unicast address since response messages typically copy the peer address
         if (Get<Mle::Mle>().IsAnycastLocator(messageInfoLocal.GetSockAddr()))
@@ -483,7 +498,7 @@ otError Udp::HandleMessage(Message &aMessage, MessageInfo &aMessageInfo)
     aMessageInfo.mSockPort = udpHeader.GetDestinationPort();
 
 #if OPENTHREAD_CONFIG_PLATFORM_UDP_ENABLE
-    VerifyOrExit(IsMlePort(aMessageInfo.mSockPort));
+    VerifyOrExit(!ShouldUsePlatformUdp(aMessageInfo.mSockPort));
 #endif
 
     for (Receiver *receiver = mReceivers.GetHead(); receiver; receiver = receiver->GetNext())
@@ -533,16 +548,25 @@ exit:
     return;
 }
 
-bool Udp::IsMlePort(uint16_t aPort) const
+#if OPENTHREAD_CONFIG_PLATFORM_UDP_ENABLE
+bool Udp::ShouldUsePlatformUdp(uint16_t aPort) const
 {
-    bool isMlePort = (aPort == Mle::kUdpPort);
-
+    return (aPort != Mle::kUdpPort && aPort != Tmf::kUdpPort
 #if OPENTHREAD_FTD
-    isMlePort = isMlePort || (aPort == Get<MeshCoP::JoinerRouter>().GetJoinerUdpPort());
+            && aPort != Get<MeshCoP::JoinerRouter>().GetJoinerUdpPort()
 #endif
-
-    return isMlePort;
+    );
 }
 
+bool Udp::ShouldUsePlatformUdp(const Udp::SocketHandle &aSocket) const
+{
+    return (ShouldUsePlatformUdp(aSocket.mSockName.mPort)
+#if OPENTHREAD_FTD && OPENTHREAD_CONFIG_BACKBONE_ROUTER_ENABLE
+            || IsBackboneSocket(aSocket)
+#endif
+    );
+}
+#endif
+
 } // namespace Ip6
 } // namespace ot
diff --git a/src/core/net/udp6.hpp b/src/core/net/udp6.hpp
index 37cf6ff79..cd201aecf 100644
--- a/src/core/net/udp6.hpp
+++ b/src/core/net/udp6.hpp
@@ -595,11 +595,15 @@ private:
 
     void AddSocket(SocketHandle &aSocket);
     void RemoveSocket(SocketHandle &aSocket);
-    bool IsMlePort(uint16_t aPort) const;
+#if OPENTHREAD_CONFIG_PLATFORM_UDP_ENABLE
+    bool ShouldUsePlatformUdp(uint16_t aPort) const;
+    bool ShouldUsePlatformUdp(const SocketHandle &aSocket) const;
+#endif
 
 #if OPENTHREAD_FTD && OPENTHREAD_CONFIG_BACKBONE_ROUTER_ENABLE
     void                SetBackboneSocket(SocketHandle &aSocket);
-    const SocketHandle *GetBackboneSockets(void);
+    const SocketHandle *GetBackboneSockets(void) const;
+    bool                IsBackboneSocket(const SocketHandle &aSocket) const;
 #endif
 
     uint16_t                 mEphemeralPort;