Configuring SD-WAN load balancing
Specify the SD-WAN load balancing method that you want the FortiGate to use for all Internet traffic between SD-WAN interface members.
Specify the SD-WAN load balancing method – GUI
- Go to Network > SD-WAN Rules.
- Select the rule named sd-wan and select Edit.
The load balancing options are displayed.
- In the Load Balancing Algorithm field, select one of the following options:
- Click OK.
GUI option |
Description |
Additional configuration steps |
---|---|---|
Source IP |
The FortiGate divides traffic equally between the interfaces included in the SD-WAN interface. However, sessions that start at the same source IP address use the same path. This is the default. |
None |
Sessions |
The FortiGate distributes the work load based on the number of sessions that are connected through the interfaces. The FortiGate uses the weight that you assign to each interface to calculate a percentage of the total sessions that are allowed to connect through each interface. The FortiGate then distributes the number of sessions between the interfaces accordingly. Sessions with the same source and destination IP addresses ( |
In the Weight column, set a weight distribution (integer value) for each interface. The pie chart shows the percentage of sessions that are distributed between the interfaces. |
Spillover |
If the amount of traffic bandwidth on an interface exceeds the ingress or egress thresholds that you set for that interface, the FortiGate sends additional traffic through one of the other SD-WAN member interfaces. |
In the Ingress Spillover Threshold column, set a threshold (in kbps) for each interface. In the Egress Spillover Threshold column, set a threshold (in kbps) for each interface. The pie chart shows the percentage of spillover thresholds that are distributed between the interfaces. |
Source-Destination IP |
The FortiGate divides traffic equally between the interfaces included in the SD-WAN interface. However, sessions that start at the same source IP address and go to the same destination IP address use the same path. |
None |
Volume |
The FortiGate distributes the work load based on the amount of packets going through the interfaces. The FortiGate uses the volume weight that you assign to each interface to calculate a percentage of the total bandwidth that’s allowed to go through each interface. The FortiGate then distributes the bandwidth between the interfaces accordingly. |
In the Weight column, set a weight distribution (integer value) for each interface. The pie chart shows the percentage of bandwidth that’s distributed between the interfaces. |
Specify the SD-WAN load balancing method – CLI
config system virtual-wan-link
set load-balance-mode {source-ip-based | weight-based | usage-based | source-dest-ip-based | measured-volume-based}
end
Where you set one of the following options:
CLI option |
Description |
Additional configuration steps |
---|---|---|
|
This is the same as the Source IP option in the GUI. |
None |
|
This is the same as the Sessions option in the GUI. |
Set a weight for each interface: config members edit <sequence_number> set weight <weight> next end The range is 0 to 255. |
|
This is the same as the Spillover option in the GUI. |
Set ingress and egress thresholds for each interface: config members edit <sequence_number> set spillover-threshold <threshold> set ingress-spillover-threshold <threshold> next end The range for both thresholds is 0 to 16776000 kbps. |
|
This is the same as the Source-Destination IP option in the GUI. |
None |
|
This is the same as the Volume option in the GUI. |
Set a volume weight for each interface: config members edit <sequence_number> set volume-ratio <weight> next end The range is 0 to 255. |