I'm writing an app that lets a user host our pages on their domains. To do that, they need to configure a couple records in their DNS. One is a TXT record with a unique value just to prove ownership. The other is for directing traffic to our site, and for that we have three options.
A CNAME record would work, but cannot be combined with the TXT record (CNAME needs to be the only record per RFC). An A record would work and would allow a TXT record as well, but we want to avoid using IPs directly because then it's hard to migrate to a different IP.
So we're looking into an NS record that points to our DNS. The problem is that while it's possible to configure a single domain with both an NS record and a TXT record, when you query for the TXT record on the original domain you get nothing, and I think it's because of the NS record. The TXT record query hits the customer's domain which says "My name server is over there", and THAT nameserver has no TXT record.
Is there any way to combine both an NS record and a TXT record on a single domain and still be able to get the value of the TXT record from the original server?