diff --git a/console/src/main/java/org/zstack/console/ManagementServerConsoleProxyBackend.java b/console/src/main/java/org/zstack/console/ManagementServerConsoleProxyBackend.java
index 664d2a127fa..f54778651e1 100755
--- a/console/src/main/java/org/zstack/console/ManagementServerConsoleProxyBackend.java
+++ b/console/src/main/java/org/zstack/console/ManagementServerConsoleProxyBackend.java
@@ -480,11 +480,34 @@ private void handle(UpdateConsoleProxyAgentMsg msg) {
             ConsoleProxyAgentVO vo;
             String oldProxyIp;
             int oldProxyPort;
-            int newProxyPort = msg.getConsoleProxyPort() == 0 ? CoreGlobalProperty.CONSOLE_PROXY_PORT : msg.getConsoleProxyPort();
+            int newProxyPort = msg.getConsoleProxyPort() == null ? CoreGlobalProperty.CONSOLE_PROXY_PORT : msg.getConsoleProxyPort();
 
 
             @Override
             public void setup() {
+                flow(new NoRollbackFlow() {
+                    String __name__ = "verify-console-proxy-port";
+                    @Override
+                    public void run(FlowTrigger trigger, Map data) {
+                        if (msg.getConsoleProxyPort() == null) {
+                            trigger.next();
+                            return;
+                        }
+
+                        ShellUtils.ShellRunner runner = new ShellUtils.ShellRunner();
+                        runner.setCommand(String.format("netstat -nltp4 | grep -E '%d\\s+'", msg.getConsoleProxyPort()));
+                        runner.setVerbose(false);
+                        runner.setWithSudo(true);
+                        runner.setSuppressTraceLog(true);
+                        ShellResult res = runner.run();
+                        String stdout = res.getStdout();
+                        if (res.getRetCode() == 0) {
+                            trigger.fail(argerr("there is other process using the port: %s", stdout));
+                        } else {
+                            trigger.next();
+                        }
+                    }
+                });
                 flow(new Flow() {
                     String __name__ = "update-console-proxy-agent-vo";
                     @Override
diff --git a/core/src/main/java/org/zstack/core/CoreGlobalProperty.java b/core/src/main/java/org/zstack/core/CoreGlobalProperty.java
index ff1759b1cb1..393face30d3 100755
--- a/core/src/main/java/org/zstack/core/CoreGlobalProperty.java
+++ b/core/src/main/java/org/zstack/core/CoreGlobalProperty.java
@@ -61,11 +61,11 @@ public class CoreGlobalProperty {
     public static boolean IS_UPGRADE_START;
     @GlobalProperty(name = "shadowEntityOn", defaultValue = "false")
     public static boolean SHADOW_ENTITY_ON;
-    @NumberRange({1024, 49151})
+    @NumberRange({1, 65535})
     @GlobalProperty(name = "consoleProxyPort", defaultValue = "4900")
     public static int CONSOLE_PROXY_PORT;       // for vnc
     @GlobalProperty(name = "httpConsoleProxyPort", defaultValue = "4901")
-    @NumberRange({1024, 49151})
+    @NumberRange({1, 65535})
     public static int HTTP_CONSOLE_PROXY_PORT;  // for terminal
     @GlobalProperty(name = "consoleProxyCertFile", defaultValue = "")
     public static String CONSOLE_PROXY_CERT_FILE;
diff --git a/header/src/main/java/org/zstack/header/console/APIUpdateConsoleProxyAgentMsg.java b/header/src/main/java/org/zstack/header/console/APIUpdateConsoleProxyAgentMsg.java
index 16c44692e0f..b9f2792ea65 100755
--- a/header/src/main/java/org/zstack/header/console/APIUpdateConsoleProxyAgentMsg.java
+++ b/header/src/main/java/org/zstack/header/console/APIUpdateConsoleProxyAgentMsg.java
@@ -18,14 +18,14 @@ public class APIUpdateConsoleProxyAgentMsg extends APIMessage implements Console
     private String uuid;
     @APIParam
     private String consoleProxyOverriddenIp;
-    @APIParam(required = false)
-    private int consoleProxyPort;
+    @APIParam(required = false, numberRange={1, 65535})
+    private Integer consoleProxyPort;
 
-    public int getConsoleProxyPort() {
+    public Integer getConsoleProxyPort() {
         return consoleProxyPort;
     }
 
-    public void setConsoleProxyPort(int consoleProxyPort) {
+    public void setConsoleProxyPort(Integer consoleProxyPort) {
         this.consoleProxyPort = consoleProxyPort;
     }
 
diff --git a/header/src/main/java/org/zstack/header/console/APIUpdateConsoleProxyAgentMsgDoc_zh_cn.groovy b/header/src/main/java/org/zstack/header/console/APIUpdateConsoleProxyAgentMsgDoc_zh_cn.groovy
index acaa07c57f0..914e5a128c3 100644
--- a/header/src/main/java/org/zstack/header/console/APIUpdateConsoleProxyAgentMsgDoc_zh_cn.groovy
+++ b/header/src/main/java/org/zstack/header/console/APIUpdateConsoleProxyAgentMsgDoc_zh_cn.groovy
@@ -62,7 +62,7 @@ doc {
 					enclosedIn "updateConsoleProxyAgent"
 					desc ""
 					location "body"
-					type "int"
+					type "Integer"
 					optional true
 					since "4.1.0"
 				}
diff --git a/sdk/src/main/java/org/zstack/sdk/UpdateConsoleProxyAgentAction.java b/sdk/src/main/java/org/zstack/sdk/UpdateConsoleProxyAgentAction.java
index 4e34b0ea324..da6a400c4b6 100644
--- a/sdk/src/main/java/org/zstack/sdk/UpdateConsoleProxyAgentAction.java
+++ b/sdk/src/main/java/org/zstack/sdk/UpdateConsoleProxyAgentAction.java
@@ -31,8 +31,8 @@ public Result throwExceptionIfError() {
     @Param(required = true, nonempty = false, nullElements = false, emptyString = true, noTrim = false)
     public java.lang.String consoleProxyOverriddenIp;
 
-    @Param(required = false, nonempty = false, nullElements = false, emptyString = true, noTrim = false)
-    public int consoleProxyPort = 0;
+    @Param(required = false, nonempty = false, nullElements = false, emptyString = true, numberRange = {1L,65535L}, noTrim = false)
+    public java.lang.Integer consoleProxyPort;
 
     @Param(required = false)
     public java.util.List systemTags;
diff --git a/test/src/test/groovy/org/zstack/test/integration/console/ConsoleProxyCase.groovy b/test/src/test/groovy/org/zstack/test/integration/console/ConsoleProxyCase.groovy
index a02602cc64d..94f1fb161d0 100644
--- a/test/src/test/groovy/org/zstack/test/integration/console/ConsoleProxyCase.groovy
+++ b/test/src/test/groovy/org/zstack/test/integration/console/ConsoleProxyCase.groovy
@@ -195,6 +195,14 @@ class ConsoleProxyCase extends SubCase {
         }
 
         ConsoleProxyAgentVO agent = dbf.listAll(ConsoleProxyAgentVO)[0]
+
+        updateConsoleProxyAgent {
+            uuid = agent.uuid
+            consoleProxyOverriddenIp = "127.0.0.2"
+        }
+        agent = dbf.reload(agent)
+        assert agent.consoleProxyOverriddenIp == "127.0.0.2"
+        
         updateConsoleProxyAgent {
             uuid = agent.uuid
             consoleProxyOverriddenIp = "127.0.0.1"