If you have a domain registered by your own domain registrar, then after NoDowntime.Domains does the failover web hosting setup for you, you must replace your existing server names with these server names below:
dns1.nodowntimedomains.com with IP: 126.96.36.199
dns2.nodowntimedomains.com with IP: 188.8.131.52
ns3.nodowntimedomains.com with IP: 184.108.40.206
ns4.nodowntimedomains.com with IP: 220.127.116.11
You should allow at least 48 hours for full DNS propagation of the new server names through the Internet worldwide.