Load balancing : Load balancing among links : Link load balancing for outbound traffic : Defining your pool of ISP links
 
Defining your pool of ISP links
You can configure FortiADC to route outgoing traffic using a pool of ISP links called a link group.
To configure a link group, create the group and then add your ISP links to it. Enter the IP address of the next-hop router (gateway) for each ISP’s link, as well as a weight that determines the proportion of outgoing sessions it receives.
For example, if the Dispatch Algorithm is WRR, FortiADC distributes outbound traffic using a weighted round-robin method. ISP links with a higher Weight value receive more traffic.
To configure FortiADC to avoid the link if your network cannot access a crucial IP address through it, specify a health check for the link (“Monitoring link health or availability”).
To configure an ISP link group and its members
1. Go to Link Load Balance > Outbound > Link Group.
2. For Name, enter a name that identifies the link group in the web UI.
3. If you want the FortiADC to select a link for outgoing traffic according to the proximity routing configuration, select Proximity Route.
For more information on proximity routing, see “Configuring routing by most efficient route or static route”.
4. For Dispatch Algorithm, select the method that FortiADC uses to select a link for outgoing traffic.
WRR
FortiADC dispatches new connections to link members using a weighted round-robin method.
Inbound Traffic
FortiADC dispatches new connections to the link member with least inbound traffic.
Outbound Traffic
FortiADC dispatches new connections to the link member with least outbound traffic.
Total Traffic
FortiADC dispatches new connections to the link member with least total traffic (that is, inbound plus outbound).
Connection
FortiADC dispatches new connections to the link member with the smallest number of connections.
Rampup
FortiADC dispatches new connections to the link member that has the lowest rate of new connections per second.
SpillOver
FortiADC dispatches new connections to the first link in the list of links until the SpillOver threshold is exceeded, and then dispatches new connections to the next link in the list until its threshold is exceeded, and so on.
5. For Persistence, select a configuration that maintains the outgoing gateway for packets with a specific source or destination IP address.
For more information on creating these configurations, see “Adding persistence to outgoing link load balancing”.
6. To define the ISP links in the pool, click Add.