Host-Based Global Load Balancing (GLB)

Global Load Balancing (GLB) allows you to distribute traffic across multiple application servers or FortiADC instances under a single Fully Qualified Domain Name (FQDN). This scenario demonstrates the Simple Host setup, where FortiADC uses DNS-based logic to return the most appropriate IP address to a client.

Setup the GLB settings

Before starting to deploy GLB-related CRDs, we need to make sure that the GLB function in FortiADC is operational.

• Enable the Global DNS Configuration

  • Go to Global Load Balance > Zone Tools. In the General Settings tab, enable Global DNS Configuration.

• Create two virtual servers

  • Go to Server Load Balance > Virtual Server. In the Virtual Server tab, create two new virtual servers named v1 and v2.

Deploy the Servers

You can download the server example and change part of the definition based on your environment. Especially the RemoteServer annotation if you want to define the FortiADC with fortiadc-ip, fortiadc-admin-port, etc.

curl -k https://raw.githubusercontent.com/fortinet/fortiadc-kubernetes-controller/main/customResource/glb/remoteserver_slb.yaml -o remoteserver_slb.yaml

curl -k https://raw.githubusercontent.com/fortinet/fortiadc-kubernetes-controller/main/customResource/glb/remoteserver_host.yaml -o remoteserver_host.yaml

Deploy it with the kubectl command:

kubectl apply -f remoteserver_slb.yaml
remoteserver.fadk8sctrl.fortinet.com/fortiadc-rs1 created

kubectl apply -f remoteserver_host.yaml
remoteserver.fadk8sctrl.fortinet.com/generic-rs1 created

Deploy the Host

You can download the host example and modify parts of the definition to match your environment, especially the Host annotations used to define the FortiADC settings such as fortiadc-ip and fortiadc-admin-port.

curl -k https://raw.githubusercontent.com/fortinet/fortiadc-kubernetes-controller/main/customResource/glb/host.yaml -o host.yaml 

Deploy it with the kubectl command:

kubectl apply -f host.yaml 

host.fadk8sctrl.fortinet.com/simple-host created 

Get the information of the simple-host by using the kubectl describe command:

# kubectl describe host simple-host 

Name:         simple-host 

Namespace:    default 

Labels:       fadcr=true 

Annotations:  fortiadc-admin-port: 443 

              fortiadc-ctrl-log: enable 

              fortiadc-ip: 172.31.5.197 

              fortiadc-login: fad-login 

API Version:  fadk8sctrl.fortinet.com/v1alpha1 

Kind:         Host 

Metadata: 

  Creation Timestamp:  2025-11-24T09:52:50Z 

  Generation:          1 

  Resource Version:    1797237 

  UID:                 54fd070f-c353-4e7f-9a32-1797a289382b 

Spec: 

  Domain:        host1.com. 

  feedbackIPv4:  0.0.0.1 

Events:                      <none> 

FortiView

Check the deployed Host and RemoteServer with FortiView.

To access the FQDN www.host1.com using the dig tool:

dig @192.168.1.108 www.host1.com +short
20.20.20.2

Update or delete the Host

To update a host resource:

You can edit the host.yaml. and use kubectl apply or use the kubectl edit command.

kubectl edit host simple-host

To delete the host resource:

kubectl delete host/simple-host