[Panino]

Poor wording. Verisign operates .com for the US government. So if Verisign's .com servers were to go down, then .com would go down with them. The author shouldn't have used the word "registrar" which makes people think of the creation of new domain names, à la GANDI (good) or GoDaddy (bad).

[TeMPOraL]

What does it mean "operates .com" and ".com would go down"? Does it mean that "google.com" would suddenly stop resolving? If so, how is that possible given the way DNS works? If not, what exactly is the panic about?

[oarsinsync]

Most DNS resolvers come with a 'root zone hints file', which includes a list of the root nameservers and static IPs for each one.

When you look up google.com, these root nameservers are queried for com, and they return the results (name and IP) for the nameservers for .com

These nameservers for com are then queried for google.com, which then return the results for the nameservers for google.com.

Google's nameservers are then queried for google.com, and an IP is returned.

So yes, given how DNS works, all .com and .net domains would stop resolving if the Verisign nameservers for .com and .net were to go down. Most people go through caching nameservers, which would retain the values for google.com, and continue to return them, up until the time to live on those records expired, at which point they too would stop returning any values if the upstream servers hadn't returned before then.

[jameshart]

Indeed. The term for the manager of a TLD, as Verisign is for .com and .net, is a 'domain registry', not registrar.