NSAPI DNS query IP version check for non LWIP stacks.

Author: tymoteuszblochmobica

features/netsocket/nsapi_dns.cpp

@@ -487,6 +487,11 @@ static nsapi_size_or_error_t nsapi_dns_query_multiple(NetworkStack *stack, const
             break;
         }
 
+        if(dns_addr.get_ip_version() != version){
+            retries = MBED_CONF_NSAPI_DNS_RETRIES;
+            index++;
+            continue;
+        }
         // send the question
         int len = dns_append_question(packet, 1, host, version);
 
@@ -1025,6 +1030,11 @@ static void nsapi_dns_query_async_send(void *ptr)
             return;
         }
 
+        if(dns_addr.get_ip_version() != query->version){
+            query->dns_server++;
+            continue;
+        }
+
         err = query->socket->sendto(dns_addr, packet, len);
 
         if (err < 0) {