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I'm moving a bunch of sites to a new hosting service. They are explaining to me that I need to run my own DNS, which they are advising that I simply set a host name pointer at my registrar for dns1.foo.com and dns2.foo.com to the static IP address of the new virtual server. Then all the sites specify those two as their nameservers. I tried it, and it works.
I admit this is not my area of expertise but it seems to me to be a weak link to have all name resolution for these sites dependent on a host name setting at the registrar.
As an alternative, I experimented with a vanity DNS I have configured at AWS Route 53, simply adding glue records there that point new subs dns5 and dns6 to the static IP address of the server. This routing works, my test sites all resolve using those as their nameservers.
So, what is the better answer here - the simple "host name" DNS pointer at the registrar, or use my vanity DNS for the mapping, at Route 53?