diff --git a/src/rest/resource.cpp b/src/rest/resource.cpp
index 0bb73413b1d..328ee485c12 100644
--- a/src/rest/resource.cpp
+++ b/src/rest/resource.cpp
@@ -125,10 +125,6 @@ Resource::Resource(ControllerOpenThread *aNcp)
     mResourceCallbackMap.emplace(OT_REST_RESOURCE_PATH_DIAGNOETIC, &Resource::HandleDiagnosticCallback);
 }
 
-void Resource::Init(void)
-{
-}
-
 void Resource::Handle(Request &aRequest, Response &aResponse) const
 {
     std::string url = aRequest.GetUrl();
@@ -519,33 +515,21 @@ void Resource::UpdateDiag(std::string aKey, std::vector<otNetworkDiagTlv> &aDiag
 
 void Resource::Diagnostic(const Request &aRequest, Response &aResponse) const
 {
-    otbrError error = OTBR_ERROR_NONE;
     OT_UNUSED_VARIABLE(aRequest);
+
     struct otIp6Address rloc16address = *otThreadGetRloc(mInstance);
     struct otIp6Address multicastAddress;
 
-    VerifyOrExit(otThreadSendDiagnosticGet(mInstance, &rloc16address, kAllTlvTypes, sizeof(kAllTlvTypes),
-                                           &Resource::DiagnosticResponseHandler,
-                                           const_cast<Resource *>(this)) == OT_ERROR_NONE,
-                 error = OTBR_ERROR_REST);
-    VerifyOrExit(otIp6AddressFromString(kMulticastAddrAllRouters, &multicastAddress) == OT_ERROR_NONE,
-                 error = OTBR_ERROR_REST);
-    VerifyOrExit(otThreadSendDiagnosticGet(mInstance, &multicastAddress, kAllTlvTypes, sizeof(kAllTlvTypes),
-                                           &Resource::DiagnosticResponseHandler,
-                                           const_cast<Resource *>(this)) == OT_ERROR_NONE,
-                 error = OTBR_ERROR_REST);
+    SuccessOrExit(otThreadSendDiagnosticGet(mInstance, &rloc16address, kAllTlvTypes, sizeof(kAllTlvTypes),
+                                            &Resource::DiagnosticResponseHandler, const_cast<Resource *>(this)));
+    SuccessOrExit(otIp6AddressFromString(kMulticastAddrAllRouters, &multicastAddress));
+    SuccessOrExit(otThreadSendDiagnosticGet(mInstance, &multicastAddress, kAllTlvTypes, sizeof(kAllTlvTypes),
+                                            &Resource::DiagnosticResponseHandler, const_cast<Resource *>(this)));
 
 exit:
 
-    if (error == OTBR_ERROR_NONE)
-    {
-        aResponse.SetStartTime(steady_clock::now());
-        aResponse.SetCallback();
-    }
-    else
-    {
-        ErrorHandler(aResponse, HttpStatusCode::kStatusInternalServerError);
-    }
+    aResponse.SetStartTime(steady_clock::now());
+    aResponse.SetCallback();
 }
 
 void Resource::DiagnosticResponseHandler(otError              aError,
diff --git a/src/rest/resource.hpp b/src/rest/resource.hpp
index 51efcafd92a..0928d265d2d 100644
--- a/src/rest/resource.hpp
+++ b/src/rest/resource.hpp
@@ -65,13 +65,6 @@ class Resource
      */
     Resource(ControllerOpenThread *aNcp);
 
-    /**
-     * This method initialize the Resource handler.
-     *
-     *
-     */
-    void Init(void);
-
     /**
      * This method is the main entry of resource handler, which find corresponding handler according to request url
      * find the resource and set the content of response.
diff --git a/src/rest/rest_web_server.cpp b/src/rest/rest_web_server.cpp
index 0fb490a00ba..246aeca1827 100644
--- a/src/rest/rest_web_server.cpp
+++ b/src/rest/rest_web_server.cpp
@@ -71,7 +71,6 @@ RestWebServer *RestWebServer::GetRestWebServer(ControllerOpenThread *aNcp)
 
 void RestWebServer::Init(void)
 {
-    mResource.Init();
     InitializeListenFd();
 }
 
diff --git a/tests/rest/CMakeLists.txt b/tests/rest/CMakeLists.txt
index e0899440b9d..f6ba89dc634 100644
--- a/tests/rest/CMakeLists.txt
+++ b/tests/rest/CMakeLists.txt
@@ -39,3 +39,7 @@ set_tests_properties(rest-server PROPERTIES
 set_tests_properties(rest-server PROPERTIES
                     LABELS "TESTREST" 
 )
+
+set_tests_properties(rest-server PROPERTIES
+                    TIMEOUT 60 
+)
diff --git a/tests/rest/test-rest-server b/tests/rest/test-rest-server
index deaccd369f4..2e268830d30 100755
--- a/tests/rest/test-rest-server
+++ b/tests/rest/test-rest-server
@@ -58,6 +58,12 @@ wait
 EOF
     trap on_exit EXIT
     sleep 5
+    sudo "${CMAKE_BINARY_DIR}"/third_party/openthread/repo/src/posix/ot-ctl factoryreset
+    sleep 1
+    sudo "${CMAKE_BINARY_DIR}"/third_party/openthread/repo/src/posix/ot-ctl ifconfig up
+    sleep 1
+    sudo "${CMAKE_BINARY_DIR}"/third_party/openthread/repo/src/posix/ot-ctl thread start
+    sleep 3
     sudo python3 "${CMAKE_CURRENT_SOURCE_DIR}"/test_rest.py
 }
 
diff --git a/tests/rest/test_rest.py b/tests/rest/test_rest.py
index 6a846489f38..6b83846b3e8 100644
--- a/tests/rest/test_rest.py
+++ b/tests/rest/test_rest.py
@@ -41,11 +41,14 @@ def assert_is_ipv6_address(string):
     assert (type(ipaddress.ip_address(string)) is ipaddress.IPv6Address)
 
 def get_data_from_url(url, result, index):
-    response = urllib.request.urlopen(urllib.request.Request(url))
-    body = response.read()
-    data = json.loads(body)
-    result[index] = data
 
+    try:    
+        response = urllib.request.urlopen(urllib.request.Request(url))
+        body = response.read()
+        data = json.loads(body)
+        result[index] = data
+    except urllib.error.HTTPError as e:
+        print(e.code)   
 
 def get_error_from_url(url, result, index):
     try: