SDWAN loadbalance inbandwidth

[Ahmed-hassan]

Hello,

Anyone can explain sdwan maximize BW loadbalance by inbandwidth, how it will loadbalane the traffic,  every session will go to interface with high free bw ?

[vponmuniraj]

Hi,

SDWAN will choose the interface with the highest available downstream bandwidth for sending out the traffic. 

Ensure to set the estimated upstream / downstream bandwidth for the interfaces. 

Regards,

[Rathan_FTNT]

Hello Ahmed,

• Maximize Bandwidth (SLA) (load-balance:( Traffic is distributed among all available links based on the selected load balancing algorithm.

When using Maximize Bandwidth mode (load-balance in the CLI), SD-WAN will all of the links that satisfies SLA to forward traffic based on a round‑robin load balancing algorithm.
Refer : 

https://docs.fortinet.com/document/fortigate/6.2.10/cookbook/708464/sd-wan-rules-maximize-bandwidth-...

When using Maximize Bandwidth mode (load-balance in the CLI), SD-WAN will choose all of the links that satisfies SLA to forward traffic based on a load balancing algorithm. The load balancing algorithm, or hash method, can be one of the following:

round-robin	All traffic are distributed to selected interfaces in equal portions and circular order. This is the default method, and the only option available when using the GUI.
source-ip-based	All traffic from a source IP is sent to the same interface.
source-dest-ip-based	All traffic from a source IP to a destination IP is sent to the same interface.
inbandwidth	All traffic are distributed to a selected interface with most available bandwidth for incoming traffic.
outbandwidth	All traffic are distributed to a selected interface with most available bandwidth for outgoing traffic.
bibandwidth	All traffic are distributed to a selected interface with most available bandwidth for both incoming and outgoing traffic.

When the inbandwidth, outbandwidth), or bibandwidth load balancing algorithm is used, the FortiGate will compare the bandwidth based on the configured upstream and downstream bandwidth values.

The interface speedtest can be used to populate the bandwidth values based on the speedtest results. See Manual interface speedtest for details.

[Ahmed-hassan]

Any information please

[Ahmed-hassan]

Thanks for information, 

Could you please identify the way that the traffic selected , 

as example 

is it will be by each traffic session fortigate will choose the free available BW ? or it will be by each packet or by each source ip 

[akileshc]

Good day, Ahmed.

When you set an SDWAN rule with Maximize Bandwidth mode (load balancing algorithm) and the default hash technique roundrobin(Which can be changed from CLI if required), the following action is taken for the traffic.

1. SD-WAN will choose (select interfaces) all links that meet SLA to route traffic.

2. All traffic (session) is distributed in equal portions and in a circular pattern to specified interfaces.

(inbandwidth, outbandwidth), or bibandwidth, is an available hash-mode used when the sdwan rule is configured with a load balancing algorithm. To route traffic, the FortiGate will compare the bandwidth depending on the configured upstream and downstream bandwidth values.

"inbandwidth" --> All incoming traffic is routed to the interface with the most available bandwidth.
"outbandwidth" --> All traffic is routed to the interface with the most available outgoing bandwidth.
"bibandwidth" --> For both incoming and outgoing traffic, all traffic is routed to the interface with the most available bandwidth.

CLI Commands:

# config sys sdwan

(sdwan) # config service

(service) # edit 1

(1) # set mode load-balance

(1) # set hash-mode round-robin/source-ip-based/source-dest-ip-based/inbandwidth/outbandwidth/bibandwidth

(1) #end