feat(domains&dns): add name server info (#4262)

Author: nerda-codes

network/domains-and-dns/concepts.mdx

@@ -64,6 +64,13 @@ An FQDN consists of a [hostname](#hostname), a [subdomain](#subdomain), a domain
 
 <Lightbox src="scaleway-fqdn.webp" alt="" />
 
+
+## Glue record
+
+A glue record is a DNS record that provides the IP address of a name server when the name server's domain is the same as the domain it is serving. Glue records ensure that DNS resolvers can find the name server's IP address without needing to resolve the domain name it is associated with.
+
+This helps ensure efficient DNS resolution for domains with name servers that are subdomains of the same domain.
+
 ## Hostname
 
 When looking at a [fully qualified domain name](#fully-qualified-domain-name-fqdn), the hostname usually comes before the domain name or the subdomain. A hostname is a label or name assigned to a computer, device, or server on a network. It helps identify and locate a specific computer or any device connected to a network among all the others.

network/domains-and-dns/how-to/manage-nameservers-internal-domain.mdx

@@ -7,19 +7,26 @@ content:
   paragraph: Learn how to effectively manage name servers for your internal domains. This guide covers editing name server information, adding and removing name servers, and validating configurations through the intuitive Domains and DNS dashboard.
 tags: nameserver internal-domain domain dns
 dates:
-  validation: 2024-08-19
+  validation: 2025-01-21
   posted: 2022-10-31
 categories:
   - network
 ---
 
 Scaleway Domains and DNS provides a managed DNS solution by providing default name servers for each domain name. If you want to use your own DNS servers, you can edit the name servers associated with your domain name.
 
+When adding name servers with Domains and DNS, you must ensure that they are [resolvable](/network/domains-and-dns/concepts/#domain-name-resolution) in the DNS. Each name server must have [A](/network/domains-and-dns/reference-content/understanding-dns-records/#a-record) and/or [AAAA](/network/domains-and-dns/reference-content/understanding-dns-records/#aaaa-record) records. These records link the name server's domain name (for example `ns0.mydomain.com`) to its corresponding IP address.
+
+This is a critical step, especially when configuring [glue records](/network/domains-and-dns/concepts/#glue-record), which are necessary for resolving domain names in cases where the name servers are within the same domain.
+
+For example, if you own `mydomain.com` and want to use `ns0.mydomain.com` and `ns1.mydomain.com` as your name servers, you must first create A/AAAA records for `ns0` and `ns1` in the `mydomain.com` DNS zone. This links `ns0.mydomain.com` and `ns1.mydomain.com` to their respective IP addresses, making them resolvable.
+
 <Macro id="requirements" />
 
 - A Scaleway account logged into the [console](https://console.scaleway.com)
 - [Owner](/identity-and-access-management/iam/concepts/#owner) status or [IAM permissions](/identity-and-access-management/iam/concepts/#permission) allowing you to perform actions in the intended Organization
 - A domain name registered with Scaleway Domains and DNS
+- Created an [A record](/network/domains-and-dns/reference-content/understanding-dns-records/#a-record) or an [AAAA record](/network/domains-and-dns/reference-content/understanding-dns-records/#aaaa-record) for the name servers you want to manage
 
 1. Click **Domains and DNS** in the **Network** section of the [Scaleway console](https://console.scaleway.com) side menu. The Domains and DNS dashboard displays.
 2. Click the domain name you want to configure. The **Overview** tab for your domain displays.