# Example: Setting up Multi-Link and dynamic DNS updates

When you set up dynamic DNS updates, the Server Pool NetLink addresses that correspond to the available Internet connections are updated automatically on the DNS server.

The administrators at Company A have already configured a Server Pool (see the previous example). Now they want to make sure that web services remain available even when an Internet connection fails. They also want the Server Pool’s NetLink addresses to be automatically updated on the DNS server based on the availability of the Internet connections.

The administrators have already configured Multi-Link routing with the necessary NetLink elements to represent each of their Internet connections. A DNS server has also already been set up in the network. The administrators decide to add the NetLinks to the Server Pool and set up Dynamic DNS (DDNS) updates.

The administrators do the following:

1. Configure the DNS server to accept DDNS updates from the firewall.
2. Edit the NetLink elements to add probe IP addresses for testing the NetLinks’ status.
3. Edit the Server Pool element’s properties and replace the default Not Specified NetLink with the NetLink elements that represent their Internet connections.
4. Define an External DNS Server element to represent the DDNS-capable server in the SMC.
5. Enable dynamic DNS updates and configure the dynamic DNS settings in the Server Pool element’s properties.