Does a Primary and Secondary DNS have different numbers?
Typically, your internet service provider will have more than one DNS server. If one server is down (say for maintainence), the other one(s) can take over the load. Some ISPs, however, have some sort of “high availablity” setup. For example, there are two computers, and they both have their own IP addresses, but whichever one is “active”, has a 3rd address. If the server with that 3rd address goes down, the other server starts answering to the 3rd address. So in this HA type scenario, you only have one address (that “3rd address” that “floats” between the two computers) for a DNS server – but that one address should have multiple servers behind it to keep in operation. It’s equally possible that your ISP has more than one DNS server, but you only know about the one.
