# Failed to Start the Trap Listener Service - Unable to Bind to Port 162

## Problem

You get an error as "Unable to bind to port" when attempting to start the Trap Listener Service from the SNMP Trap Receiver tool.

## Cause

You will get this error in the following cases:

1. When the port is already in use  
2. When OpUtils is run as a normal user in Linux OS and when the Trap Port number is less than 1024  

## Resolution

**Check whether the port is already in use**

From the command prompt, check whether the trap port is in use using the command: **netstat -aon**. For example, if you have not changed the default trap port (162), you will get to see a line similar to below in Windows OS:

```
UDP - 0.0.0.0:162 - *:* - 680
```

This means that the port 162 is already bound by some application whose process id is 680. You can either kill this process from the Task Manager and try starting the Trap Listener Service from OpUtils or change the Trap Port to a different number and start.

**Note:** If you are changing the Trap Port, the device which sends traps to OpUtils should also be configured to send traps to this port.

**Start OpUtils as a Root User in Linux OS**

In Linux OS, if you want to bind any application to ports between 1 and 1023, you require superuser privilege. This means you should start OpUtils as a root user/super user to start the trap service at port 162.

**Applies to:** [SNMP Trap Receiver](https://www.manageengine.com/products/oputils/snmp-tools.html#trap)

**Keywords:** SNMP, SNMP Traps, Trap Listener, Trap Manager, Trap Port, UDP Port

Enhance your network management with all the free [SNMP Tools](https://www.manageengine.com/products/oputils/snmp-tools.html) available.

## 24/5 Support

Support will be available 24 hours a day and five days a week (Monday through Friday), excluding USA & India public holidays.

Tel : +1-888-720-9500