I have an odd problem which I haven't been able to even find mentioned elsewhere. A while back, I switched out the Wifi access points as well as the router for a small office network. After I did this, most everything started working better, with one exception:
2–3 times per office day, lasting around 10–15 minutes, the users can't visit any Google sites when using Chrome. During these times, every Chrome user has to switch over to some other browser for a few minutes to be able to access Google Drive, Gmail, the Google search engine and so on.
I have read online that some people who have problem accessing sites in general through Chrome report that unchecking "use a prediction service to load pages more quickly" helps, but this has not solved my problem.
The three work-arounds I've found so far are restarting the Chrome Browser, and just waiting the problem out. Neither of these are satisfactory solutions, because they are unwelcome and unpredictable interruptions in the work day.
During these occurrences, the status bar of Chrome says "Waiting for XXX", where XXX is any Google domain the user is trying to visit. This leads me to believe it's not a DNS problem. (If it were, it would say "Looking up XXX" instead.)
I suspect this is some weird case where the Chrome browser assumes the router should be configured to let a particular kind of TCP message through, and when it gets dropped, Chrome waits until it times out. I read something, somewhere about IPv6, so maybe Chrome knows Google supports IPv6 and tries that first, until it times out and then tries IPv4 a while? No idea.
The irregularity and short duration of these occurrences makes it really hard to troubleshoot (by switching to a different connection, trying on a different operating system, sniffing packets and so on).
For the record, the configuration stack where I know this happens:
- Mac OS X 10.8–10.11
- Chrome 48–50
- UniFi AP-AC-Lite
- UniFi EdgeRouter PoE
The network is a simple, single LAN with the router as the default gateway.