Safeguard DNS service unreliable?

[#1]

For a month or so, have been having problems with the home network intermittently reporting no internet access and having just used the router's built-in diagnostics, see it's reporting DNS problems. I had set the router to use the safeguard servers (as specified here).

To confirm this, if use a command line ping of the primary Safeguard DNS server, I get...

> ping 213.120.234.42

Pinging 213.120.234.42 with 32 bytes of data:
Reply from 213.121.192.61: Destination net unreachable.
Request timed out.
Reply from 213.121.192.61: Destination net unreachable.
Request timed out.

Ping statistics for 213.120.234.42:
    Packets: Sent = 4, Received = 2, Lost = 2 (50% loss),

The main DNS server does respond, so I could probably change the routers set up, but with younger ones in the house,  I would prefer to use the safer option.

[#2]

From your post it appears you have a router that allows direct setting of DNS servers.

If you wish to change from the Safeguard servers but still would like some paraental control then have a look at OpenDNS and it's Family Shield https://umbrella.cisco.com/blog/2010/06/23/introducing-familyshield-parental-controls/

[#3]

Thanks. Will look into it.