We have an RV016 (hardware version 2, firmware version 3.0.2.01) behind a cable modem.
Attached to this RV016 is a switch to which our other devices are connected. Among those is another switch, a wireless access point and our VOIP phone system.
The issue with this setup seems to be as follows:
The Mac machines at our office seem to be unable to get internet access reliably. What we have observed is that a connection to the wireless access point is made. Google will load fine, then when performing a search it comes back with either a dns lookup error or just says that the site can't be found. Sometimes sites will load just fine, sometimes they don't. Our Windows or Ubuntu machines in our office hardly ever have that issue, but they do on occasion. Essentially internet is usable on Windows and Ubuntu, but not on a newer Mac. Mainly three Macs are affected that run a newer OS. Two other Macs (older OS) seem to be fine. My coworkers (who have that issue at work) report that at home they do not.
The DNS servers on the router were set to our ISPs addresses. I have since changed them to opendns servers. The issue persists.
When connecting a MacBook directly to the cable modem, everything works fine. Since we are using NAT, I do need to use the router. There are devices attached to it that these users need to be able to get to.
When hooking up the wireless access point to the cable modem, service is fine too. It all seems to point to the router. If someone could offer advice that would be great.