Thank you for helping me...I just realize that my ip address is wrong.

@celonunes Yes I already done it like this right
mqtt:mymosquitto.url=tcp://192.168.1.13:1883
mqtt:mymosquitto.clientId=MQTT

@celonunes: Actualy I just follow this link exactly :
www.instructables.com/id/Garage-Genie-Parking-Remote-Control/?ALLSTEPS

Step (After all the connection and installation done):
1-open mosquitto in command windows
2-open openHAB start.bat

error at
2015-03-11 00:38:03.979 [ERROR] [.io.transport.mqtt.MqttService] - Error starting broker connection

org.eclipse.paho.client.mqttv3.MqttException: Unable to connect to server

3- open arduino serial monitior
error connecting to mqtt

Hi I need anybody to help me regarding openHAB and Mosquitto to communicate with arduino mega + w5100 ethernet shield.

I already install and followed all the installation step on both openHAB and Mosquitto.
www.instructables.com/id/Garage-Genie-Parking-Remote-Control/?ALLSTEPS

But, I got an error on openHAB:

2015-03-11 00:38:03.979 [ERROR] [.io.transport.mqtt.MqttService] - Error starting broker connection

org.eclipse.paho.client.mqttv3.MqttException: Unable to connect to server

at org.eclipse.paho.client.mqttv3.internal.TCPNetworkModule.start(TCPNetworkModule.java:75) ~[na:na]

at org.eclipse.paho.client.mqttv3.internal.ClientComms$ConnectBG.run(ClientComms.java:538) ~[na:na]

at java.lang.Thread.run(Unknown Source) ~[na:1.8.0_40]

Caused by: java.net.ConnectException: Connection timed out: connect

at java.net.DualStackPlainSocketImpl.waitForConnect(Native Method) ~[na:1.8.0_40]

at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source) ~[na:1.8.0_40]

at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source) ~[na:1.8.0_40]

at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source) ~[na:1.8.0_40]

at java.net.AbstractPlainSocketImpl.connect(Unknown Source) ~[na:1.8.0_40]

at java.net.PlainSocketImpl.connect(Unknown Source) ~[na:1.8.0_40]

at java.net.SocksSocketImpl.connect(Unknown Source) ~[na:1.8.0_40]

Arduino error:
error connecting to MQTT

Please, help me
Tq.