SD-WAN lowest cost (SLA) strategy

[BensonLEI]

Hi, guys,

We are using Forti400e pair with FortiOS v6.4.3. 

From the FortiOS administration guide V6.4.4 ( page 600 ) for this SD-WAN strategy, the example states as below:

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In this example, your wan1 and wan2 SD-WAN interfaces connect to two ISPs that both go to the public internet. The cost of wan2 is less than that of wan1. You want to configure Gmail services to use the lowest cost interface, but the link quality must meet a standard of latency: 10ms, and jitter: 5ms.

To configure an SD-WAN rule to use Lowest Cost (SLA):

1. On the FortiGate, add wan1 and wan2 as SD-WAN members, then add a policy and static route. See SD-WAN quick start on page 558 for details.

2. Create a new Performance SLA named google that includes an SLA Target with Latency threshold = 10ms and Jitter threshold = 5ms. See Link monitoring example on page 582.

3. Go to Network > SD-WAN Rules.

4. Click Create New. The Priority Rule page opens. 5. Enter a name for the rule, such as gmail.

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For this strategy, I set up different costs for some WAN links ( my goal is for hot link-failover based on cost): 

1. I want to set up SD-WAN rule based on the costs value only ?

any advice or recommendation ?

many thanks