Namerservers & A Records, what's the best server setup for my predicament?

Question

Right now we have a very thoroughly developed web app sitting on https://domain.com. It is built in ASP.NET. We want to build a separate site now, that solely advertises the app, handles all the marketing for the app. We want to use WordPress. Unfortunately, our current server setup does not allow for a php based CMS.

But I suspect we can build the marketing site on another server entirely and use some sort of dns record to forward users to the app, or to the CMS, depending on which is better.

So we'd be looking to move the app to something like app.domain.com and have domain.com be the WordPress marketing site, on another server.

From my understanding, this is doable using an A record. However, I have a few concerns.

If I look up the WHOIS for domain.com it is currently using 5 nameservers. I don't have a complete understanding of why we have 5 and how it corresponds to our server IP.

If we move to another server, change the nameservers and create an A Record to point app.domain.com to an IP address, am I losing any server reliability? It feels like I am losing the reliability of having the 5 nameservers, I don't fully grasp how it relates to the IP address. Is there an issue here I should be concerned about?

Better yet, is it possible to create an A Record for the root domain? That way we could leave the nameservers as they are and just have domain.com resolve from somewhere else. Are there any issues I should be aware of here?

Also, something to consider, we regularly have scheduled updates/maintenance that we make to the app and at times our servers are offline. Where are dns records kept? If they are down will an A record still resolve?

Answer 1

So you have a domain domain.com which is hosted under server which only supports Microsoft Technologies and you wanted to add something.domain.com which you intended to be built with PHP. There is no need to change Name servers to gain what you wanted. Just get hold of the control panel which is hosting your DNS (usually web hosting company itself serves as the DNS holder) and add a A record to point to new server's ip which will be serving something.domain.com.

Multiple NS server for your domain means your dns service provider is load balancing their dns servers.

If your web servers are offline and someone visits your site, the domainname will get resolved but it will return an error since the server which is supposed to respond is down.

Get acquainted with DNS with some primer.It will surely help a lot.