In safari, and several other products, I get a network timeout where I have to reload the page, even though I have a full / working Wifi connection.
This is a sporadic issue.
The problem seems to occur after I installed Cisco's security product "OpenDNS Umbrella". Removing OpenDNS Umbrella seems to fix the problem.
I would like to get a better understanding of the network layers in macOS so I can create an appropriate trace/diagnostic for review.
What are the "layers" of software that are available for extension and modification in macOS? (I'm from a Windows Mindset and understand MSFT's well-documented network API, packet filters, and what extensions are available etc).
How can I create a trace of network activity at the aforementioned layers? For example, I want to see not just DNS traces, but any internal firewall that could be affecting me? (macOS has a built-in firewall that might be giving me trouble.)
I did briefly install "Little Snitch" firewall program, but I then uninstalled it. I'm not sure if this is relevant, but it does manage connections via an API I'm not aware of.