> ## Documentation Index
> Fetch the complete documentation index at: https://docs.aviatrix.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Gateway Keepalive

> The keepalive speed is a global configuration that applies to all Aviatrix gateways. Aviatrix gateways send periodic keepalive messages to the Aviatrix Controller that enables the Controller to determine when a gateway's state changes to monitor when a gateway is down.

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The keepalive speed is a global configuration that applies to all Aviatrix
gateways. Aviatrix gateways send periodic keepalive messages to the Aviatrix
Controller that enables the Controller to determine when a gateway's state
changes to monitor when a gateway is down.

The following table shows how frequently gateways send keepalive messages and
how often the Controller processes these messages.

| Speed  | Gateway sends keepalive | Down detection  |
| ------ | ----------------------- | --------------- |
| Fast   | every 2 seconds         | every 7 seconds |
| Medium | every 12 seconds        | every 1 minute  |
| Slow   | every 1 minute          | every 5 minutes |

By default, the keepalive speed is set to **Medium**.

A gateway is considered to be in the **UP** state if the Controller receives at
least 2 (out of a possible 5) messages from that gateway between two consecutive
health checks. For example:

When set to **Fast**, the gateway down detection time is between 7 seconds and
14 seconds.

When set to **Medium**, the gateway down detection time is between 1 minute to 2
minutes.

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## Changing Gateway Keepalive Setting

To change the keepalive speed:

1. In Aviatrix CoPilot, go to **Settings > Configuration > General** tab.
2. In the **General** tab, expand the **Advanced** section.
3. Under **Advanced** section, in **Gateway to Controller Communication**, from
   the **Keep-Alive Speed** dropdown menu, select the speed.
4. Click **Save**.