Most domains can have up to 13 name servers assigned at the registry, most domain registrars will let you setup 6 or more (mine does 6). Ideally you'd have your

Most domains can have up to 13 name servers assigned at the registry, most domain registrars will let you setup 6 or more (mine does 6). Ideally you'd have your registrars and another source hosting your dns and keep them synced up. Unless you have a weird edge case most of the time its set it up once and forget it. This way even if you registrar has problems you have another dns that is still up. Do a dig on some popular domains (like google,cnn,etc) and you'll see they have multiple dns entries by different providers. If your website is important enough to keep up in case your registrar is not, then you need it hosted by multiple providers including your registrar (its usually free, why not right).