Milesight LoRaWAN Gateway supports different network interfaces, including the Ethernet, Dual Cellular and WIFI, which is used to make the router online by different ways, it supports to detect whether it's online, if it lost the internet, Gateway will switch it to next available interface automatically.
Before using the Link Failover feature, we need to make sure there are at least two Links available, for example, the Cellular and the WAN interface.
This is the status of cellular module. The SIM card is installed well and it's connected to mobile carrier already.
This is the WAN port's status, it's connected to the switch and configured well.
To trigger the link failover rule, the gateway will starts to detect the destination address using ICMP, which means the gateway will ping the address configured in SLA page by the scheduled interval. If there is no response on both addresses, the current Link will be regarded as 'Down', the Backup Interface will take it over to send the sensor data to your server platform.
In this example, the gateway will ping 114.114.114.114 and 8.8.8.8 every 15 seconds, if there is no reply for 3 times, the link failover rule will be triggered.
There is a default Link Failover, which makes the Cellular as the primary interface, and the WAN port is the backup.
If you want to make the WAN as the primary interface, you can change it here.
In addition, since Milesight UG85 and UG87 supports Dual SIM card, it works in cold standby mode as well. We can configure the Primary SIM card here, if SIM1 is selected, then the SIM2 will be standby.
Ps.
1. To check which route was used currently, we can try the trace route tool on 'Maintenance->Tools' page to get it.
2.The ping detection will lead to cellular data usage. You can adjust the 'Data Size' and the 'Interval' value to reduce it.