Load Balancing Mode and Tie Break Setting In SDWAN

[tungnx59]

Dear Experts, 

I don't understant load-balacing mode and tie break option on service configuration of SDWAN Fortigate.

I think if traffic match sdwan rule and have >= 2 paths match SLA, traffic will be load balanced base on hash mode ?

And so what is purpose of tie break option ? If set it to enable, the option will override load balancing option?

Or tie break just only run when all paths don't meet SLA ?

Thank you in advance !

[spoojary]

The load balancing mode in SD-WAN rules on FortiGate allows you to distribute traffic across multiple paths based on the configured load balancing algorithm (hash mode). When multiple paths meet the SLA requirements, traffic will be load-balanced according to the hash mode specified.  the tie break option is used to handle situations where multiple paths have equal SLA values, ensuring traffic is directed to a specific path based on the tie break criteria configured, overriding the load balancing algorithm in such cases.

[tungnx59]

Hi @spoojary 

Example:

I have SLA 1: Jitlter: 10ms, Latency: 10ms, Packet loss: 2%.

I have 2 paths meet SLA defined ( < SLA 1) and they are diferent SLAs, so Fortigate will use hash mode to load balancing traffic over these paths, right ?

If 2 path have same SLA (6ms, 5ms, lost 1%) and still meet SLA defined, so FGT will Tie break to choose one of 2 path to steering traffic ?

If 2 path don't meet SLA, Tie break also will be used to choose 1 path ?

Thank you in advance !