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.
- On the FortiGate, enable SD-WAN and add wan1 and wan2 as SD-WAN members, then add a policy and static route. See Creating the SD-WAN interface 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.
config system virtual-wan-link config health-check edit "server" set server "188.8.131.52" set update-static-route enable set members 1 2 next end end
FGT # diagnose sys virtual-wan-link 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