automatic restart of dhcp after gateway restart

[hboetes]

The 4g gateway of our guest WLAN often crashes, after which I have to restart the DHCP client on the opnsense firewall so it picks up the changes. Now restarting the 4g gateway is something my colleagues can do without me, but for restarting the DHCP client you need access. I already set up monitoring the gateway, but how can I ensure the WAN interface is restarted? Or is there a more elegant solution?

Thanks!
Han