This happens quite often for me: I turn on my GNU/Linux boxen and try to browse the web. Firefox takes a long time start up, then when I enter something like google.com, it takes a while to get there, or even fails to get there. Gmail would be working, then at some point says that the internet isn’t reachable.
In these moments, I ping google.com from console and see this:
In this case, IPv6 is not working properly for you.
When I ran into that problem, I would reboot the router and that would fix it. That’s worth trying, but it might not help in your case. Whether it helps depends on the router, your ISP and other factors.
At present, after changing ISP, I don’t have IPv6 access at all – which is a different problem.
Not really. What you describe seems fairly normal.
Many routers have a built in functionality to monitor internet connectivity, and to restart if that fails. But often they only monitor IPv4 connectivity, and don’t notice problems with IPv6 connectivity.
With my former ISP, the router would find a problem and reset after being up for around 90 days. But it began to have IPv6 problems after around 60 days. So I monitored that myself, and manually restarted when problems showed up.
If IPv6 is completely unreliable for you, then you can disable it in your operating system (Yast/System/Network Settings). If it works for a while, then maybe monitor the router and restart it when there are problems.
If you are having problems with IPv6,
Then you might try changing your YaST DHCP settings to assign IPv4 addresses only.
Considering the increasing use of IPv6, I would spend some time troubleshooting your IPv6 problems… Would recommend usual steps to run trace route (IPv6) to see if the problem is your own equipment, your ISP or someone else.