Greetings

I am now quite desperate!!
Have had about 3 (maybe its 4 already) times in the last 6 weeks where
I have DNS issues.
Have a terrible ISP on fixed wireless that is very clear that they
have NO assistance for *nix users - - - - and mz googly is always
their friend.

(Running devuan daedalus on my main system (haven't yet moved to
excalibur but that's going to happen RSN.)
Issue this time:

after wakeup go to computer - - - not able to access the web
check router - - - WAN is accessible
ping 8.8.8.8 destination unreachable
ping router - - (WTF) destination unreachable
power cycle the router
can now ping 8.8.8.8 but not mz googly.ca
have wireless access to the web (this is the weird part imo)
I call tech support - - - they tell me to just clear the DNS cache on my puter
sadly - - - this is something I do not know how to do (!!!)
looking on the web - - - I can't find anything for sysV init systems
(can for systemd but that's it!! - - - argh!)

Is there someone out there that can help me with either the command(s)
or the process so I don't have to reboot my system to clear my DNS
issues - - - please?

TIA