cable-modem/router to router

Hi folks, this question is home-network related, but it's about chaining routers/firewalls, so I thought I would start here.

Configuration
"Inner Router"
I have a Netgear WNDR4500 router/firewall connected to a Zoom 5352 Cable-Modem/Router/firewall combo (I want the extra protection of having the firewalls "chained" if that makes sense). All my home devices are connected to the WNDR4500 (either wired or wireless). I have the WNDR4500 set up as a DHCP server with ip addresses between 192.168.2.2 and 192.168.2.254. The WNDR4500 ip address itself is 192.168.2.1 with a subnet mask is 255.255.255.0. Dns is set to openDNS as primary and google as the secondary.

"Outer Router/Modem"
On the Zoom 5352 Wireless is disabled, ip address of router is 192.168.0.1. It is set up as a Router (as opposed to a bridge: is this correct?)

It mostly works. Mostly. The problem is that there are times when the service requests take a very long time to resolve (timing out in some cases; not frequently, but not rarely either). Speedtest, when it connects okay (it doesn't always), shows pretty low ping times (<30ms) and speeds consistent with my plan (105mb down, 5mb up).

I guess I am a little confused as to whether it should be in bridge or router mode. If I'm in bridge mode, am I still getting the benefit of both firewalls?

Thanks for any assistance

 

Update: I found what might *potentially* be a culprit. Enabling IP Flood Detection in the Zoom firewall seems to be causing at least some of the problem.

 

And no sooner after accidentally stumbling across the "potential" solution, I did a google search on Zoom 5352 flood detection and found this post (ugh can't post links yet because my post count is too low) on their tech support forums, confirming it. Now I'm curious as to why it's fundamentally broken in the first place, but at least my tcp requests aren't mysteriously going off into the weeds anymore.

Just google search for "zoom 5352 ip flood detection" and it's the first link that comes up.