@Clive_A 

Hi, i'm using ER605 in standalone mode, connected to WAN with Dynamic IP to ZTE 5G modem in IP passtrough. When modem disconnect and reconnect, getting new IP, i have to wait very very long time to get new IP on ER605 side. 

Here the log with Online Detection "Always Online":

2024-12-30 16:25:35    LOGGER    NOTICE    [WAN] of [24-2F-D0-6D-EA-F0] is up.
2024-12-30 16:24:57    DHCP Client    NOTICE    WAN: DHCP client getting IP succeeded. (IP-Address=10.11.xx.xxx, Mask=255.255.255.252, Gateway=10.11.xx.xxx)
2024-12-30 16:24:56    LOGGER    NOTICE    [WAN] of [24-2F-D0-6D-EA-F0] is down.
2024-12-30 16:15:05    DHCP Client    NOTICE    WAN: DHCP client lease expired. Began renewing the lease.

Here the log with Online Detection "Auto":

2024-12-30 17:05:36    LOGGER    NOTICE    [WAN] of [24-2F-D0-6D-EA-F0] is up.
2024-12-30 17:05:06    ONLINE_DECTION    NOTICE    [24-2F-D0-6D-EA-F0]: The online detection result of [WAN] was online.
2024-12-30 17:04:59    DHCP Client    NOTICE    WAN: DHCP client getting IP succeeded. (IP-Address=10.17.xx.xx, Mask=255.255.255.252, Gateway=10.17.xx.xx)
2024-12-30 17:04:57    LOGGER    NOTICE    [WAN] of [24-2F-D0-6D-EA-F0] is down.
2024-12-30 16:54:54    DHCP Client    NOTICE    WAN: DHCP client lease expired. Began renewing the lease
2024-12-30 16:50:21    ONLINE_DECTION    NOTICE    [24-2F-D0-6D-EA-F0]: The online detection result of [WAN] was offline.

After WAN is UP, i also have to wait an other minute (whitout any log!) to get Internet accessible to client (ethernet connected).
Why such a behaviour? 

I know in ideal world the modem should notify router to force getting new IP, but it seems nor zyxel nor zte do it. Why Online Detection cannot be used to force a reconnection of WAN interface? Other brand routers doing it without any problem.