# Update GRE configuration with dynamic addresses

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## Description

Running a GRE tunnel over IPSec with IKEv2 is a common scenario. This is easy to configure on client, but has an issue on server side: client IP addresses are assigned dynamically via mode-config and have to be updated for GRE interface.

This script handles the address updates and disables the interface if the client is disconnected.

## Requirements and installation

Just install the script:

```
$ScriptInstallUpdate update-gre-address;
```

... and add a scheduler to run the script periodically:

```
/ system scheduler add interval=30s name=update-gre-address on-event="/ system script run update-gre-address;" start-time=startup;
```

## Configuration

The configuration goes to interface's comment. Add the client's IKEv2 certificate CN into the comment:

```
/ interface gre set comment="ikev2-client1" gre-client1;
```

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