Link Load Balancing : Configuring gateway links
 
Configuring gateway links
The gateway link configuration enables you to specify health checks, bandwidth rate thresholds, and spillover threshold behavior for the gateway links you add to link groups.
Before you begin:
You must know the IP addresses of the ISP gateway link used in the network segment where the FortiADC appliance is deployed.
You must have added health check configuration objects that you want to use to probe the gateway links.
You must have Read-Write permission for Link Load Balance settings.
After you have configured a gateway link configuration object, you can select it in the link group configuration.
To configure a gateway link:
1. Go to Link Load Balance > Link Group.
2. Click the Gateway tab.
3. Click Add to display the configuration editor.
4. Complete the configuration as described in Table 20.
5. Save the configuration.
 
Table 20: LLB gateway configuration
Settings
Guidelines
Name
Unique name. No spaces or special characters.
After you initially save the configuration, you cannot edit the name.
Address
IP address of the gateway link.
Total Spillover Threshold
Maximum total bandwidth rate (inbound plus outbound) for a link in a spillover load balancing pool.
Inbound Bandwidth
Maximum bandwidth rate for inbound traffic through this gateway link. This is a global setting that applies to all traffic received from this gateway link. If traffic exceeds this threshold, the FortiADC system considers the gateway to be full and does not dispatch new connections to it.
The default is 2,147,483,647 Kbps, which is also the maximum configurable value. We recommend you tune bandwidth thresholds strategically, using the bandwidth rate and price structure agreement you have with your ISP to your advantage.
Outbound Bandwidth
Maximum bandwidth rate for outbound traffic.
Inbound Spillover Threshold
Maximum inbound bandwidth rate for a link in a spillover load balancing pool.
If you enable spillover load balancing in the link group configuration, the system maintains a spillover list. It dispatches new connections to the link with the greatest priority until its spillover threshold is exceeded; then dispatches new connections to the link with the next greatest priority until its threshold is exceeded, and so on.
This is a global setting that applies to all traffic received from this gateway link. If traffic exceeds this threshold, the FortiADC system considers the gateway to be full and does not dispatch new connections to it.
Outbound Spillover Threshold
Maximum outbound bandwidth rate for a link in a spillover load balancing pool.
Health Check
Enable and select a health check configuration. Optional.