We have recently changed from an End of Life cisco router to the ER605.  The staff are reporting regular but intermittent internet loss.  We are all fairly non-technical, and are trying to understand if it a setting on the new router - which we are pretty much using the out of the box config right now, other than cloning the cable modem IP for the WAN - or if we have an ISP issue.   Topography is Rogers cable modem -> ER605 -> office desktop PC

What logging would need to be enabled on the ER605 router and what would we be looking for in the logs, that would identify each time internet connectivity through the ISP is lost?  The Cable modem is pass-thru. 

I checked the user guide here but the System Log settings in chapter 8 just offer Severity level and there is no documentation on what severity the router would consider no internet access.

Thanks in advance