/ip dns set primary-dns=188.8.131.52
/ip dns set secondary-dns=184.108.40.206
Make sure you set the correct IP addresses!
Why setup dns at all? The only time I see DNS being used by the router is when it is being a proxy server or the DHCP service retrieves those settings to hand out. But if you are unable to use a domain name in settings and you aren't using proxy or DHCP on that router, what is the point of setting it up in the first place?
/system ntp client print
The primary is Tock, a US NAVY server and the scondary is a NIST server. Most of the routers we've deployed simply use 220.127.116.11.
You should avoid using public stratum 1 time servers from all your routers directly.
The suggested configuration is to have 1 or 2 time servers on your network that tracks the time from servers like that and the rest of your machines on your network use your own time servers for reference.
Or use the NTP Pool Project
which was started in 2003 as a response to the rapidly increasing resource consumption at the popular NTP servers and the problem of these servers then closing their operations.
I currently run two time servers that all my routers and servers use. The first one has been running since July 2002 and has about 6-7 good public servers, including tock.usno.navy.mil & time-b.nist.gov. The second server is newer and uses 0.us.pool.ntp.org,1.us.pool.ntp.org & 2.us.pool.ntp.org. But I am currently planning a change in my network that will be including a re-numbering of some servers and would like to not have to reconfigure the IP addresses everywhere, so I might try Lenti's suggestion:
/system ntp client set primary-ntp=[:resolve 0.pool.ntp.org]
/system ntp client set secondary-ntp=[:resolve 1.pool.ntp.org]