Check our DD-WRT startup script you should be able to easily tweak it to use it with your provider. If OpenVPN isn't running then it restarts the OpenVPN process (instead of the router). Also I would disable the "Connection Watchdog" that will only add extra issues and not solve any.
The Notifier works in conjunction with the Watchdog of your dd-wrt router. It will send out an email (using an ESMTP protocol) for any device that exceeds the connection limit you specified in the configuration. Watchguard Firebox II - DD-WRT Wiki Introduction: The Watchguard Firebox series are usually based on standard x86 processors, so this information may apply to a wider variety of Watchguard routers.Even though this guide is intended for the Firebox II, it also applies to the Firebox III and Firebox x700 as well, due to similar hardware designs. DD-WRT: Setting up a WDS for your home. - YouTube Nov 24, 2014
Using DD-WRT's WDS feature : homelab
Buffalo's DD-WRT Reviewed - SmallNetBuilder - Results from #2
To enable watchdog connection in dd wrt devices, Step 1) Go to "Administration" Step 2) Go to "Keep Alive" Step 3) "Enable" watchdog Step 4) Enter Interval. Screenshot example shows 360s Step 5) Enter IP Address. My favorite Example: 8.8.8.8 To enter multiple ip address, leave a space between the ip address: x.x.x.x y.y.y.y z.z.z.z
Feb 08, 2009 DD-WRT Forum :: View topic - Proxy/Connection Watchdog