# TCP & UDP Monitoring

Source: https://instatus.com/help/monitoring/tcp-udp

TCP and UDP monitors allow you to verify that your servers and applications are reachable over specific network ports.  
They're ideal for monitoring databases, mail servers, application backends, DNS servers, game servers, VoIP gateways, or any service that listens on a TCP or UDP port.

Just like with [other monitors](https://instatus.com/help/monitoring), if a TCP or UDP monitor detects a problem, your team can quickly [investigate and resolve it](https://instatus.com/help/incident-response) and keep users informed via your [status page](https://instatus.com/help/status-page).

![Monitor](https://instatus.com/help/monitors/item.png)

## What TCP Monitors Do

- Test whether a host and port are reachable from multiple global locations.
- Detect when a service goes offline, becomes slow to respond, or drops connections.
- Measure connection time and latency.
- Send alerts to your preferred communication channels when connectivity issues occur.
- Display uptime statistics on your status page.

## What UDP Monitors Do

- Check if a target host and UDP port are reachable.
- Measure packet loss and response latency.
- Detect when a UDP-based service stops responding or becomes unstable.
- Track uptime and reliability across multiple global locations.
- Display performance metrics on your public or internal status page.

## Setting Up a TCP Monitor

To create a new monitor, go to your project → Monitors → Add monitor.

![Add TCP monitor](https://instatus.com/help/monitors/tcp.png)

### Monitor type

Choose **TCP** from the monitor type list.

![TCP monitor type](https://instatus.com/help/monitors/type-tcp.png)

Then enter the **host:port** you want to monitor.  
For example:  
`db.yourcompany.com:5432` or `mail.example.com:25`

### How TCP checks work

A TCP monitor attempts to open a socket connection to the target host and port at regular intervals.  
If the connection succeeds, the monitor is marked as **successful**.  
If the connection fails or is refused, the monitor is marked as **down**.

## Setting Up a UDP Monitor

To add one, go to your project → Monitors → Add monitor.

![Add UDP monitor](https://instatus.com/help/monitors/udp.png)

### Monitor type

Select **UDP** from the list of available monitor types.

![UDP monitor type](https://instatus.com/help/monitors/type-udp.png)

Enter the **hostname or IP address** and **port** you want to monitor. For example:  
`8.8.8.8:53` or `192.168.1.1:53`

### How UDP checks work

UDP monitors send packets to the configured host and port at set intervals.  
If a valid response is received within the timeout period, the monitor is considered **healthy**.  
If there's no response or too much packet loss, it's marked as **down** or **degraded**.

## Advanced Options

![Advanced monitor settings](https://instatus.com/help/monitors/advanced-settings.png)

- **Friendly name:** Add a label so you can easily identify your monitor.
- **Run checks every:** Decide how frequently to test the connection.
- **Run from:** Choose where to test from (United States, Canada, Europe, Asia).
- **Add to status page:** Display this service's uptime and response time publicly.
- **When a monitor fails:** Initiate an incident, notify subscribers, or publish to your status page.
- **When a monitor recovers:** Resolve incidents and automatically update your status page.

Your TCP or UDP monitor is now keeping an eye on your ports!

- [DNS Monitoring](https://instatus.com/help/monitoring/dns): Learn how to monitor DNS servers and services by testing DNS queries