Link monitoring example
Performance SLA link monitoring measures the health of links that are connected to SD-WAN member interfaces by sending probing signals through each link to a server and measuring the link quality based on latency, jitter, and packet loss. If a link is broken, the routes on that link are removed, and traffic is routed through other links. When the link is working again, the routes are reenabbled. This prevents traffic being sent to a broken link and lost.
In this example:
- Interfaces wan1 and wan2 connect to the internet through separate ISPs
- The detection server IP address is 22.214.171.124
A performance SLA is created so that, if one link fails, its routes are removed and traffic is detoured to the other link.
To configure a Performance SLA using the GUI:
- On the FortiGate, add wan1 and wan2 as SD-WAN members, then add a policy and static route. See SD-WAN quick start for details.
- Go to Network > Performance SLA.
- Click Create New. The Performance SLA page opens.
- Enter a name for the SLA and select a protocol.
- In the Server field, enter the detection server IP address (126.96.36.199 in this example).
- In the Participants field, select both wan1 and wan2.
- Configured the remaining settings as needed, then click OK.
To configure a Performance SLA using the CLI:
config system sdwan config health-check edit "server" set server "188.8.131.52" set update-static-route enable set members 1 2 next end end
To diagnose the Performance SLA status:
FGT # diagnose sys sdwan health-check Health Check(server): Seq(1): state(alive), packet-loss(0.000%) latency(15.247), jitter(5.231) sla_map=0x0 Seq(2): state(alive), packet-loss(0.000%) latency(13.621), jitter(6.905) sla_map=0x0