How not to distribute DNS servers

For one of our customers that addresses the south american market, we’ve rented a server at HostDime in Brazil. Unfortunately, they often suffer network outages. Once again, we can’t reach our server, so I try to access their Ticket system named “Core”. It’s unreachable, too. Let’s see: $ host core.hostdime.com.br Host core.hostdime.com.br not found: 3(NXDOMAIN) Okay, [...]