Turn off firmware check for RBR40?

Would be an interesting topic to document..... but not trivial.

Netgear routers do not provide a simple, easy mechanism to capture what is happening on the WAN link.  Many routers have a "debug" option, but alas that rapidly fills the memory buffer and thus does not capture very much data.  What I did was effective, but took a bit of work:

• Insert a managed Ethernet switch between the router and ISP modem.
• Connect one switch port to the router WAN port.
• Connect another switch port to the modem.
• Connect a third switch port to a computer than can run Wireshark.
• Set up the switch to mirror the WAN port to the Wireshark port (both incoming and outgoing).
• On the computer, set Wireshark with a capture filter to save only the desired information.  (no sense in capturing gigabytes of traffic)
• Let Wireshark capture data long enough to capture the desired information.  My first experiment was to capture DHCP for over a week, which documented that
  o  Spectrum assigns IPv4 addresses with a lease time of 86,400 seconds (one day), and
  o  IPv6 addresses with a lease time of 604,800 seconds (one week), and
  o My Orbi router renewed the leases exactly as predicted (when they had 50% of the lease time remaining).

Documenting how often the router "checked in" with Netgear was a bit more complicated.

• The first step was to discover the IP addresses which lead to updates1.netgear.com.  This involved recording every DNS query for a long time to find them.
  (and, there are quite a lot of them)
• Then create a Wireshark capture filter to collect only traffic between the WAN port and those specific IP addresses.
• Run this capture long enough to establish a pattern.

It was a bit annoying that the actual connection between router and Netgear is all https (encrypted).  There is a tool that can be used to decrypt it (HTTP Toolkit), but I am too cheap to pay $15/month to use it.

For your situation, the task would be to document when the router checks in with Netgear and observe if there were any "network problems" at those specific times.  My guess is that (a) nothing will correspond, and (b) this is Way more effort than it is worth.