diff --git a/TESTS/netsocket/dns/asynchronous_dns.cpp b/TESTS/netsocket/dns/asynchronous_dns.cpp
new file mode 100644
index 0000000000..8dcac3c65c
--- /dev/null
+++ b/TESTS/netsocket/dns/asynchronous_dns.cpp
@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2018, ARM Limited, All Rights Reserved
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "mbed.h"
+#include "greentea-client/test_env.h"
+#include "unity.h"
+#include "utest.h"
+#include "dns_tests.h"
+
+using namespace utest::v1;
+
+namespace {
+int result_ok;
+int result_no_mem;
+int result_dns_failure;
+int result_exp_timeout;
+}
+
+void ASYNCHRONOUS_DNS()
+{
+    do_asynchronous_gethostbyname(dns_test_hosts, 1, &result_ok, &result_no_mem, &result_dns_failure, &result_exp_timeout);
+
+    TEST_ASSERT(result_ok == 1);
+    TEST_ASSERT(result_no_mem == 0);
+    TEST_ASSERT(result_dns_failure == 0);
+    TEST_ASSERT(result_exp_timeout == 0);
+}
diff --git a/TESTS/netsocket/dns/asynchronous_dns_cache.cpp b/TESTS/netsocket/dns/asynchronous_dns_cache.cpp
new file mode 100644
index 0000000000..70283cbae9
--- /dev/null
+++ b/TESTS/netsocket/dns/asynchronous_dns_cache.cpp
@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) 2018, ARM Limited, All Rights Reserved
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "mbed.h"
+#include "greentea-client/test_env.h"
+#include "unity.h"
+#include "utest.h"
+#include "dns_tests.h"
+
+using namespace utest::v1;
+
+namespace {
+int ticker_us = 0;
+}
+
+static void test_dns_query_ticker(void)
+{
+    ticker_us += 100;
+}
+
+void ASYNCHRONOUS_DNS_CACHE()
+{
+    rtos::Semaphore semaphore;
+    dns_application_data data;
+    data.semaphore = &semaphore;
+
+    Ticker ticker;
+    ticker.attach_us(&test_dns_query_ticker, 100);
+
+    for (unsigned int i = 0; i < 5; i++) {
+        int started_us = ticker_us;
+
+        nsapi_error_t err = get_interface()->gethostbyname_async(dns_test_hosts[0],
+                                                                 mbed::Callback<void(nsapi_error_t, SocketAddress *)>(hostbyname_cb, (void *) &data));
+        TEST_ASSERT(err >= 0);
+
+        semaphore.wait();
+
+        TEST_ASSERT(data.result == NSAPI_ERROR_OK);
+        TEST_ASSERT(strlen(data.addr.get_ip_address()) > 1);
+
+        int delay_ms = (ticker_us - started_us) / 1000;
+
+        static int delay_first = delay_ms / 2;
+        // Check that cached accesses are at least twice as fast as the first one
+        TEST_ASSERT_FALSE(i != 0 && delay_ms > delay_first);
+
+        printf("DNS: query \"%s\" => \"%s\", time %i ms\n",
+               dns_test_hosts[0], data.addr.get_ip_address(), delay_ms);
+    }
+}
diff --git a/TESTS/netsocket/dns/asynchronous_dns_cancel.cpp b/TESTS/netsocket/dns/asynchronous_dns_cancel.cpp
new file mode 100644
index 0000000000..2c866cf6f7
--- /dev/null
+++ b/TESTS/netsocket/dns/asynchronous_dns_cancel.cpp
@@ -0,0 +1,84 @@
+/*
+ * Copyright (c) 2018, ARM Limited, All Rights Reserved
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "mbed.h"
+#include "greentea-client/test_env.h"
+#include "unity.h"
+#include "utest.h"
+#include "dns_tests.h"
+
+using namespace utest::v1;
+
+void ASYNCHRONOUS_DNS_CANCEL()
+{
+    rtos::Semaphore semaphore;
+    dns_application_data *data = new dns_application_data[MBED_CONF_APP_DNS_TEST_HOSTS_NUM];
+
+    int count = 0;
+
+    for (unsigned int i = 0; i < MBED_CONF_APP_DNS_TEST_HOSTS_NUM; i++) {
+        data[i].value_set = false;
+        data[i].semaphore = &semaphore;
+        data[i].req_result = get_interface()->gethostbyname_async(dns_test_hosts[i],
+                                                                  mbed::Callback<void(nsapi_error_t, SocketAddress *)>(hostbyname_cb, (void *) &data[i]));
+        TEST_ASSERT(data[i].req_result >= 0 || data[i].req_result == NSAPI_ERROR_NO_MEMORY);
+
+        if (data[i].req_result >= 0) {
+            // Callback will be called
+            count++;
+        } else {
+            // No memory to initiate DNS query, callback will not be called
+            data[i].result = NSAPI_ERROR_NO_MEMORY;
+            data[i].value_set = true;
+        }
+    }
+
+    for (unsigned int i = 0; i < MBED_CONF_APP_DNS_TEST_HOSTS_NUM; i++) {
+        if (data[i].req_result > 0) {
+            if (get_interface()->gethostbyname_async_cancel(data[i].req_result) == NSAPI_ERROR_OK) {
+                count--;
+            }
+        }
+    }
+
+    // Wait for callback(s) to complete
+    for (int i = 0; i < count; i++) {
+        semaphore.wait();
+    }
+
+    for (unsigned int i = 0; i < MBED_CONF_APP_DNS_TEST_HOSTS_NUM; i++) {
+        if (!data[i].value_set) {
+            printf("DNS: query \"%s\" => cancel\n", dns_test_hosts[i]);
+            continue;
+        }
+        TEST_ASSERT(data[i].result == NSAPI_ERROR_OK || data[i].result == NSAPI_ERROR_NO_MEMORY || data[i].result == NSAPI_ERROR_DNS_FAILURE || data[i].result == NSAPI_ERROR_TIMEOUT);
+        if (data[i].result == NSAPI_ERROR_OK) {
+            printf("DNS: query \"%s\" => \"%s\"\n",
+                   dns_test_hosts[i], data[i].addr.get_ip_address());
+        } else if (data[i].result == NSAPI_ERROR_DNS_FAILURE) {
+            printf("DNS: query \"%s\" => DNS failure\n", dns_test_hosts[i]);
+        } else if (data[i].result == NSAPI_ERROR_TIMEOUT) {
+            printf("DNS: query \"%s\" => timeout\n", dns_test_hosts[i]);
+        } else if (data[i].result == NSAPI_ERROR_NO_MEMORY) {
+            printf("DNS: query \"%s\" => no memory\n", dns_test_hosts[i]);
+        }
+    }
+
+    delete[] data;
+
+    wait(5.0);
+}
diff --git a/TESTS/netsocket/dns/asynchronous_dns_external_event_queue.cpp b/TESTS/netsocket/dns/asynchronous_dns_external_event_queue.cpp
new file mode 100644
index 0000000000..11291f5e93
--- /dev/null
+++ b/TESTS/netsocket/dns/asynchronous_dns_external_event_queue.cpp
@@ -0,0 +1,85 @@
+/*
+ * Copyright (c) 2018, ARM Limited, All Rights Reserved
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "mbed.h"
+#include "greentea-client/test_env.h"
+#include "unity.h"
+#include "utest.h"
+#include "dns_tests.h"
+
+#include "nsapi_dns.h"
+
+using namespace utest::v1;
+
+namespace {
+int result_ok;
+int result_no_mem;
+int result_dns_failure;
+int result_exp_timeout;
+
+const int EXTERNAL_THREAD_SIZE = 2048;
+const int EVENT_QUEUE_SIZE = 10;
+
+events::EventQueue *event_queue;
+}
+
+static nsapi_error_t event_queue_call(int delay, mbed::Callback<void()> func)
+{
+    if (delay) {
+        if (event_queue->call_in(delay, func) == 0) {
+            return NSAPI_ERROR_NO_MEMORY;
+        }
+    } else {
+        if (event_queue->call(func) == 0) {
+            return NSAPI_ERROR_NO_MEMORY;
+        }
+    }
+    return NSAPI_ERROR_OK;
+}
+
+void ASYNCHRONOUS_DNS_EXTERNAL_EVENT_QUEUE()
+{
+    // Ensures that cache does not contain entries
+    do_asynchronous_gethostbyname(dns_test_hosts, MBED_CONF_NSAPI_DNS_CACHE_SIZE, &result_ok, &result_no_mem,
+                                  &result_dns_failure, &result_exp_timeout);
+
+    TEST_ASSERT(result_ok == MBED_CONF_NSAPI_DNS_CACHE_SIZE);
+    TEST_ASSERT(result_no_mem == 0);
+    TEST_ASSERT(result_dns_failure == 0);
+    TEST_ASSERT(result_exp_timeout == 0);
+
+    // Dispatch event queue
+    Thread eventThread(osPriorityNormal, EXTERNAL_THREAD_SIZE);
+    EventQueue queue(EVENT_QUEUE_SIZE * EVENTS_EVENT_SIZE);
+    eventThread.start(callback(&queue, &EventQueue::dispatch_forever));
+    event_queue = &queue;
+
+    nsapi_dns_call_in_set(event_queue_call);
+
+    do_asynchronous_gethostbyname(dns_test_hosts_second, MBED_CONF_APP_DNS_SIMULT_QUERIES + 1, &result_ok, &result_no_mem,
+                                  &result_dns_failure, &result_exp_timeout);
+
+    TEST_ASSERT(result_ok == MBED_CONF_APP_DNS_SIMULT_QUERIES);
+    TEST_ASSERT(result_no_mem == 1); // last query fails for no memory as expected
+    TEST_ASSERT(result_dns_failure == 0);
+    TEST_ASSERT(result_exp_timeout == 0);
+
+    // Give event queue time to finalise before destructors
+    wait(2.0);
+
+    nsapi_dns_call_in_set(0);
+}
diff --git a/TESTS/netsocket/dns/asynchronous_dns_invalid_host.cpp b/TESTS/netsocket/dns/asynchronous_dns_invalid_host.cpp
new file mode 100644
index 0000000000..57780b26ef
--- /dev/null
+++ b/TESTS/netsocket/dns/asynchronous_dns_invalid_host.cpp
@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) 2018, ARM Limited, All Rights Reserved
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "mbed.h"
+#include "greentea-client/test_env.h"
+#include "unity.h"
+#include "utest.h"
+#include "dns_tests.h"
+
+using namespace utest::v1;
+
+namespace {
+int result_ok;
+int result_no_mem;
+int result_dns_failure;
+int result_exp_timeout;
+}
+
+void ASYNCHRONOUS_DNS_INVALID_HOST()
+{
+    // Ensures that cache does not contain entries
+    do_asynchronous_gethostbyname(dns_test_hosts_second, MBED_CONF_NSAPI_DNS_CACHE_SIZE, &result_ok, &result_no_mem,
+                                  &result_dns_failure, &result_exp_timeout);
+
+    char dns_test_hosts_new[MBED_CONF_APP_DNS_TEST_HOSTS_NUM][DNS_TEST_HOST_LEN];
+    memcpy(dns_test_hosts_new, dns_test_hosts, sizeof(dns_test_hosts_new));
+
+    int exp_dns_failure = 0;
+    int exp_ok = 0;
+
+    // Invalidate 1st and 3th etc. entries
+    for (unsigned int i = 0; i < MBED_CONF_APP_DNS_SIMULT_QUERIES + 1; i++) {
+        if ((i % 2) == 0) {
+            // Last query fails to no memory so do not increase
+            if (i != MBED_CONF_APP_DNS_SIMULT_QUERIES) {
+                exp_dns_failure++;
+            }
+            strcat(&(dns_test_hosts_new[i][0]), "_invalid");
+        } else {
+            // Last query fails to no memory so do not increase
+            if (i != MBED_CONF_APP_DNS_SIMULT_QUERIES) {
+                exp_ok++;
+            }
+        }
+    }
+
+    do_asynchronous_gethostbyname(dns_test_hosts_new, MBED_CONF_APP_DNS_SIMULT_QUERIES + 1, &result_ok, &result_no_mem,
+                                  &result_dns_failure, &result_exp_timeout);
+
+    TEST_ASSERT(result_ok == exp_ok);
+    TEST_ASSERT(result_no_mem == 1); // last query fails for no memory as expected
+    TEST_ASSERT(result_dns_failure == exp_dns_failure || result_dns_failure == exp_dns_failure + 1);
+    TEST_ASSERT(result_exp_timeout == 0);
+}
diff --git a/TESTS/netsocket/dns/asynchronous_dns_non_async_and_async.cpp b/TESTS/netsocket/dns/asynchronous_dns_non_async_and_async.cpp
new file mode 100644
index 0000000000..37831b511b
--- /dev/null
+++ b/TESTS/netsocket/dns/asynchronous_dns_non_async_and_async.cpp
@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2018, ARM Limited, All Rights Reserved
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "mbed.h"
+#include "greentea-client/test_env.h"
+#include "unity.h"
+#include "utest.h"
+#include "dns_tests.h"
+
+using namespace utest::v1;
+
+void ASYNCHRONOUS_DNS_NON_ASYNC_AND_ASYNC()
+{
+    rtos::Semaphore semaphore;
+    dns_application_data data;
+    data.semaphore = &semaphore;
+
+    // Initiate
+    nsapi_error_t err = get_interface()->gethostbyname_async(dns_test_hosts_second[0],
+                                                             mbed::Callback<void(nsapi_error_t, SocketAddress *)>(hostbyname_cb, (void *) &data));
+    TEST_ASSERT(err >= 0);
+
+    for (unsigned int i = 0; i < MBED_CONF_APP_DNS_TEST_HOSTS_NUM; i++) {
+        SocketAddress addr;
+        int err = get_interface()->gethostbyname(dns_test_hosts[i], &addr);
+        printf("DNS: query \"%s\" => \"%s\"\n",
+               dns_test_hosts[i], addr.get_ip_address());
+
+        TEST_ASSERT_EQUAL(0, err);
+        TEST_ASSERT((bool)addr);
+        TEST_ASSERT(strlen(addr.get_ip_address()) > 1);
+    }
+
+    semaphore.wait();
+
+    TEST_ASSERT(data.result == NSAPI_ERROR_OK);
+
+    printf("DNS: query \"%s\" => \"%s\"\n",
+           dns_test_hosts_second[0], data.addr.get_ip_address());
+
+    TEST_ASSERT(strlen(data.addr.get_ip_address()) > 1);
+}
diff --git a/TESTS/netsocket/dns/asynchronous_dns_simultaneous.cpp b/TESTS/netsocket/dns/asynchronous_dns_simultaneous.cpp
new file mode 100644
index 0000000000..ae99074570
--- /dev/null
+++ b/TESTS/netsocket/dns/asynchronous_dns_simultaneous.cpp
@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2018, ARM Limited, All Rights Reserved
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "mbed.h"
+#include "greentea-client/test_env.h"
+#include "unity.h"
+#include "utest.h"
+#include "dns_tests.h"
+
+using namespace utest::v1;
+
+namespace {
+int result_ok;
+int result_no_mem;
+int result_dns_failure;
+int result_exp_timeout;
+}
+
+void ASYNCHRONOUS_DNS_SIMULTANEOUS()
+{
+    do_asynchronous_gethostbyname(dns_test_hosts_second, MBED_CONF_APP_DNS_SIMULT_QUERIES + 1, &result_ok, &result_no_mem,
+                                  &result_dns_failure, &result_exp_timeout);
+
+    TEST_ASSERT(result_ok == MBED_CONF_APP_DNS_SIMULT_QUERIES);
+    TEST_ASSERT(result_no_mem == 1); // last query fails for no memory as expected
+    TEST_ASSERT(result_dns_failure == 0);
+    TEST_ASSERT(result_exp_timeout == 0);
+}
diff --git a/TESTS/netsocket/dns/asynchronous_dns_simultaneous_cache.cpp b/TESTS/netsocket/dns/asynchronous_dns_simultaneous_cache.cpp
new file mode 100644
index 0000000000..3fef74aa55
--- /dev/null
+++ b/TESTS/netsocket/dns/asynchronous_dns_simultaneous_cache.cpp
@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2018, ARM Limited, All Rights Reserved
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "mbed.h"
+#include "greentea-client/test_env.h"
+#include "unity.h"
+#include "utest.h"
+#include "dns_tests.h"
+
+using namespace utest::v1;
+
+namespace {
+int result_ok;
+int result_no_mem;
+int result_dns_failure;
+int result_exp_timeout;
+}
+
+void ASYNCHRONOUS_DNS_SIMULTANEOUS_CACHE()
+{
+    do_asynchronous_gethostbyname(dns_test_hosts_second, MBED_CONF_APP_DNS_SIMULT_QUERIES + 1, &result_ok, &result_no_mem,
+                                  &result_dns_failure, &result_exp_timeout);
+
+    // Addresses were cached on last step, OK for all
+    TEST_ASSERT(result_ok == MBED_CONF_APP_DNS_SIMULT_QUERIES + 1);
+    TEST_ASSERT(result_no_mem == 0);
+    TEST_ASSERT(result_dns_failure == 0);
+    TEST_ASSERT(result_exp_timeout == 0);
+}
diff --git a/TESTS/netsocket/dns/asynchronous_dns_simultaneous_repeat.cpp b/TESTS/netsocket/dns/asynchronous_dns_simultaneous_repeat.cpp
new file mode 100644
index 0000000000..98c8dcb685
--- /dev/null
+++ b/TESTS/netsocket/dns/asynchronous_dns_simultaneous_repeat.cpp
@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2018, ARM Limited, All Rights Reserved
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "mbed.h"
+#include "greentea-client/test_env.h"
+#include "unity.h"
+#include "utest.h"
+#include "dns_tests.h"
+
+using namespace utest::v1;
+
+namespace {
+int result_ok;
+int result_no_mem;
+int result_dns_failure;
+int result_exp_timeout;
+}
+
+void ASYNCHRONOUS_DNS_SIMULTANEOUS_REPEAT()
+{
+
+    for (int i = 0; i < 100; i++) {
+        do_asynchronous_gethostbyname(dns_test_hosts, MBED_CONF_APP_DNS_SIMULT_QUERIES + 1, &result_ok, &result_no_mem,
+                                      &result_dns_failure, &result_exp_timeout);
+
+        // For 1st round can fail to no memory, on other rounds some of the addresses are found from cache
+        TEST_ASSERT(result_ok == MBED_CONF_APP_DNS_SIMULT_QUERIES || result_ok == MBED_CONF_APP_DNS_SIMULT_QUERIES + 1);
+        TEST_ASSERT(result_no_mem == 1 || result_no_mem == 0); // last query fails for 1st round to no memory as expected
+        TEST_ASSERT(result_dns_failure == 0);
+        TEST_ASSERT(result_exp_timeout == 0);
+    }
+}
diff --git a/TESTS/netsocket/dns/asynchronous_dns_timeouts.cpp b/TESTS/netsocket/dns/asynchronous_dns_timeouts.cpp
new file mode 100644
index 0000000000..37401df1e9
--- /dev/null
+++ b/TESTS/netsocket/dns/asynchronous_dns_timeouts.cpp
@@ -0,0 +1,80 @@
+/*
+ * Copyright (c) 2018, ARM Limited, All Rights Reserved
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "mbed.h"
+#include "greentea-client/test_env.h"
+#include "unity.h"
+#include "utest.h"
+#include "dns_tests.h"
+
+#include "nsapi_dns.h"
+
+using namespace utest::v1;
+
+namespace {
+int result_ok;
+int result_no_mem;
+int result_dns_failure;
+int result_exp_timeout;
+
+const int EXTERNAL_THREAD_SIZE = 2048;
+const int EVENT_QUEUE_SIZE = 10;
+
+events::EventQueue *event_queue;
+}
+
+static nsapi_error_t event_queue_call(int delay, mbed::Callback<void()> func)
+{
+    // Run event queue without delays
+    if (event_queue->call(func) == 0) {
+        return NSAPI_ERROR_NO_MEMORY;
+    }
+
+    return NSAPI_ERROR_OK;
+}
+
+void ASYNCHRONOUS_DNS_TIMEOUTS()
+{
+    // Ensures that cache does not contain entries
+    do_asynchronous_gethostbyname(dns_test_hosts, MBED_CONF_NSAPI_DNS_CACHE_SIZE, &result_ok, &result_no_mem,
+                                  &result_dns_failure, &result_exp_timeout);
+
+    TEST_ASSERT(result_ok == MBED_CONF_NSAPI_DNS_CACHE_SIZE);
+    TEST_ASSERT(result_no_mem == 0);
+    TEST_ASSERT(result_dns_failure == 0);
+    TEST_ASSERT(result_exp_timeout == 0);
+
+    // Dispatch event queue
+    Thread eventThread(osPriorityNormal, EXTERNAL_THREAD_SIZE);
+    EventQueue queue(EVENT_QUEUE_SIZE * EVENTS_EVENT_SIZE);
+    eventThread.start(callback(&queue, &EventQueue::dispatch_forever));
+    event_queue = &queue;
+
+    // Set event queue callback to test specific one
+    nsapi_dns_call_in_set(event_queue_call);
+
+    do_asynchronous_gethostbyname(dns_test_hosts_second, MBED_CONF_APP_DNS_SIMULT_QUERIES + 1, &result_ok, &result_no_mem,
+                                  &result_dns_failure, &result_exp_timeout);
+
+    // Depends on timing, but at least one operation shall fail to timeout
+    TEST_ASSERT(result_exp_timeout > 0);
+
+    // Give event queue time to finalise before destructors
+    wait(2.0);
+
+    nsapi_dns_call_in_set(0);
+}
diff --git a/TESTS/netsocket/dns/dns_tests.h b/TESTS/netsocket/dns/dns_tests.h
new file mode 100644
index 0000000000..f393560011
--- /dev/null
+++ b/TESTS/netsocket/dns/dns_tests.h
@@ -0,0 +1,77 @@
+/*
+ * Copyright (c) 2018, ARM Limited, All Rights Reserved
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef DNS_TESTS_H
+#define DNS_TESTS_H
+
+#ifndef MBED_CONF_APP_DNS_SIMULT_QUERIES
+#define MBED_CONF_APP_DNS_SIMULT_QUERIES   5
+#endif
+
+#ifndef MBED_CONF_NSAPI_DNS_CACHE_SIZE
+#define MBED_CONF_NSAPI_DNS_CACHE_SIZE     3
+#endif
+
+// Hostnames for testing against
+// Both lists must have A and AAAA records
+#ifndef MBED_CONF_APP_DNS_TEST_HOSTS
+#define MBED_CONF_APP_DNS_TEST_HOSTS {"google.com", "youtube.com", "facebook.com", "wikipedia.org", "yahoo.com", "instagram.com"}
+#endif
+
+#ifndef MBED_CONF_APP_DNS_TEST_HOSTS_SECOND
+#define MBED_CONF_APP_DNS_TEST_HOSTS_SECOND {"ipv6ready.org", "wireshark.org", "bbc.co.uk", "cnn.com", "www.flickr.com", "www.mozilla.org"}
+#endif
+
+#ifndef MBED_CONF_APP_DNS_TEST_HOSTS_NUM
+#define MBED_CONF_APP_DNS_TEST_HOSTS_NUM 6
+#endif
+
+#define DNS_TEST_HOST_LEN 40
+
+struct dns_application_data {
+    rtos::Semaphore *semaphore;
+    nsapi_error_t result;
+    SocketAddress addr;
+    nsapi_error_t req_result;
+    bool value_set;
+};
+
+extern const char dns_test_hosts[MBED_CONF_APP_DNS_TEST_HOSTS_NUM][DNS_TEST_HOST_LEN];
+extern const char dns_test_hosts_second[MBED_CONF_APP_DNS_TEST_HOSTS_NUM][DNS_TEST_HOST_LEN];
+
+/*
+ * Utility functions
+ */
+NetworkInterface *get_interface();
+void hostbyname_cb(void *data, nsapi_error_t result, SocketAddress *address);
+void do_asynchronous_gethostbyname(const char hosts[][DNS_TEST_HOST_LEN], unsigned int op_count, int *exp_ok, int *exp_no_mem, int *exp_dns_failure, int *exp_timeout);
+
+/*
+ * Test cases
+ */
+void ASYNCHRONOUS_DNS();
+void ASYNCHRONOUS_DNS_SIMULTANEOUS();
+void ASYNCHRONOUS_DNS_SIMULTANEOUS_CACHE();
+void ASYNCHRONOUS_DNS_CACHE();
+void ASYNCHRONOUS_DNS_NON_ASYNC_AND_ASYNC();
+void ASYNCHRONOUS_DNS_CANCEL();
+void ASYNCHRONOUS_DNS_EXTERNAL_EVENT_QUEUE();
+void ASYNCHRONOUS_DNS_INVALID_HOST();
+void ASYNCHRONOUS_DNS_TIMEOUTS();
+void ASYNCHRONOUS_DNS_SIMULTANEOUS_REPEAT();
+
+#endif
diff --git a/TESTS/netsocket/dns/main.cpp b/TESTS/netsocket/dns/main.cpp
new file mode 100644
index 0000000000..9dee6b2d99
--- /dev/null
+++ b/TESTS/netsocket/dns/main.cpp
@@ -0,0 +1,153 @@
+/*
+ * Copyright (c) 2018, ARM Limited, All Rights Reserved
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef MBED_CONF_APP_CONNECT_STATEMENT
+#error [NOT_SUPPORTED] No network configuration found for this target.
+#endif
+
+#include "mbed.h"
+#include "greentea-client/test_env.h"
+#include "unity.h"
+#include "utest.h"
+#include "nsapi_dns.h"
+#include "EventQueue.h"
+#include "dns_tests.h"
+
+#include MBED_CONF_APP_HEADER_FILE
+
+using namespace utest::v1;
+
+namespace {
+NetworkInterface *net;
+}
+
+const char dns_test_hosts[MBED_CONF_APP_DNS_TEST_HOSTS_NUM][DNS_TEST_HOST_LEN] = MBED_CONF_APP_DNS_TEST_HOSTS;
+const char dns_test_hosts_second[MBED_CONF_APP_DNS_TEST_HOSTS_NUM][DNS_TEST_HOST_LEN] = MBED_CONF_APP_DNS_TEST_HOSTS_SECOND;
+
+// Callback used for asynchronous DNS result
+void hostbyname_cb(void *data, nsapi_error_t result, SocketAddress *address)
+{
+    dns_application_data *app_data = static_cast<dns_application_data *>(data);
+    app_data->result = result;
+    if (address) {
+        app_data->addr = *address;
+    }
+    app_data->semaphore->release();
+    app_data->value_set = true;
+}
+
+// General function to do asynchronous DNS host name resolution
+void do_asynchronous_gethostbyname(const char hosts[][DNS_TEST_HOST_LEN], unsigned int op_count, int *exp_ok, int *exp_no_mem, int *exp_dns_failure, int *exp_timeout)
+{
+    // Verify that there is enough hosts in the host list
+    TEST_ASSERT(op_count <= MBED_CONF_APP_DNS_TEST_HOSTS_NUM)
+
+    // Reset counters
+    (*exp_ok) = 0;
+    (*exp_no_mem) = 0;
+    (*exp_dns_failure) = 0;
+    (*exp_timeout) = 0;
+
+    // Create callback semaphore and data
+    rtos::Semaphore semaphore;
+    dns_application_data *data = new dns_application_data[op_count];
+
+    unsigned int count = 0;
+    for (unsigned int i = 0; i < op_count; i++) {
+        data[i].semaphore = &semaphore;
+        nsapi_error_t err = net->gethostbyname_async(hosts[i], mbed::Callback<void(nsapi_error_t, SocketAddress *)>(hostbyname_cb, (void *) &data[i]));
+        TEST_ASSERT(err >= 0 || err == NSAPI_ERROR_NO_MEMORY);
+        if (err >= 0) {
+            // Callback will be called
+            count++;
+        } else {
+            // No memory to initiate DNS query, callback will not be called
+            data[i].result = NSAPI_ERROR_NO_MEMORY;
+        }
+    }
+
+    // Wait for callback(s) to complete
+    for (unsigned int i = 0; i < count; i++) {
+        semaphore.wait();
+    }
+
+    // Print result
+    for (unsigned int i = 0; i < op_count; i++) {
+        TEST_ASSERT(data[i].result == NSAPI_ERROR_OK || data[i].result == NSAPI_ERROR_NO_MEMORY || data[i].result == NSAPI_ERROR_DNS_FAILURE || data[i].result == NSAPI_ERROR_TIMEOUT);
+        if (data[i].result == NSAPI_ERROR_OK) {
+            (*exp_ok)++;
+            printf("DNS: query \"%s\" => \"%s\"\n",
+                   hosts[i], data[i].addr.get_ip_address());
+        } else if (data[i].result == NSAPI_ERROR_DNS_FAILURE) {
+            (*exp_dns_failure)++;
+            printf("DNS: query \"%s\" => DNS failure\n", hosts[i]);
+        } else if (data[i].result == NSAPI_ERROR_TIMEOUT) {
+            (*exp_timeout)++;
+            printf("DNS: query \"%s\" => timeout\n", hosts[i]);
+        } else if (data[i].result == NSAPI_ERROR_NO_MEMORY) {
+            (*exp_no_mem)++;
+            printf("DNS: query \"%s\" => no memory\n", hosts[i]);
+        }
+    }
+
+    delete[] data;
+}
+
+NetworkInterface *get_interface()
+{
+    return net;
+}
+
+static void net_bringup()
+{
+    MBED_ASSERT(MBED_CONF_APP_DNS_TEST_HOSTS_NUM >= MBED_CONF_NSAPI_DNS_CACHE_SIZE && MBED_CONF_APP_DNS_TEST_HOSTS_NUM >= MBED_CONF_APP_DNS_SIMULT_QUERIES + 1);
+
+    net = MBED_CONF_APP_OBJECT_CONSTRUCTION;
+    int err =  MBED_CONF_APP_CONNECT_STATEMENT;
+    TEST_ASSERT_EQUAL(0, err);
+
+    printf("MBED: Connected to network\n");
+    printf("MBED: IP Address: %s\n", net->get_ip_address());
+}
+
+// Test setup
+utest::v1::status_t test_setup(const size_t number_of_cases)
+{
+    GREENTEA_SETUP(120, "default_auto");
+    net_bringup();
+    return verbose_test_setup_handler(number_of_cases);
+}
+
+Case cases[] = {
+    Case("ASYNCHRONOUS_DNS", ASYNCHRONOUS_DNS),
+    Case("ASYNCHRONOUS_DNS_SIMULTANEOUS", ASYNCHRONOUS_DNS_SIMULTANEOUS),
+    Case("ASYNCHRONOUS_DNS_SIMULTANEOUS_CACHE", ASYNCHRONOUS_DNS_SIMULTANEOUS_CACHE),
+    Case("ASYNCHRONOUS_DNS_CACHE", ASYNCHRONOUS_DNS_CACHE),
+    Case("ASYNCHRONOUS_DNS_NON_ASYNC_AND_ASYNC", ASYNCHRONOUS_DNS_NON_ASYNC_AND_ASYNC),
+    Case("ASYNCHRONOUS_DNS_CANCEL", ASYNCHRONOUS_DNS_CANCEL),
+    Case("ASYNCHRONOUS_DNS_EXTERNAL_EVENT_QUEUE", ASYNCHRONOUS_DNS_EXTERNAL_EVENT_QUEUE),
+    Case("ASYNCHRONOUS_DNS_INVALID_HOST", ASYNCHRONOUS_DNS_INVALID_HOST),
+    Case("ASYNCHRONOUS_DNS_TIMEOUTS", ASYNCHRONOUS_DNS_TIMEOUTS),
+    Case("ASYNCHRONOUS_DNS_SIMULTANEOUS_REPEAT",  ASYNCHRONOUS_DNS_SIMULTANEOUS_REPEAT),
+};
+
+Specification specification(test_setup, cases);
+
+int main()
+{
+    return !Harness::run(specification);
+}