Nameserver sets are a set of provisioned nameservers along with all domains and related configuration for those domains. You might think of them as projects or sub-accounts.
Nameserver sets allow you to isolate one set of domains from another set of domains. This might be to split up traffic (and reserve processing capacity for each set), to provision nameservers in different locations, or simply for organizational benefits. For example:
NS Set 1
Domains: domain1.us, domain2.us
NS Set 2
Domains: domain1.eu, domain2.eu
NS Set 3
NS Set 4
If you have domains that expressly target different regions and wish to locate DNS servers only within those regions, you could setup something like sets 1 and 2. In combination with vanity names, this could facilitate a very localized appearance of your domains.
In the case of set 3, one might choose to isolate traffic for a particular busy domain or set of domains.
As shown in set 4, some corporate setups might prefer having dedicated DNS resources just for internal domains. This could be for location reasons or just a desire to organize and separate things accordingly.
For billing purposes, we simply count the total number of provisioned nameserver instances on the account. Whether they are on one or multiple nameserver sets does not affect billing.
Note that all of these are advanced use cases and most accounts use only a single nameserver set. As always, if you have questions, we’re here to help!