Child Nameservers vs. External Zone Delegation Explained
Child nameservers are nameservers that live under your own domain (such as ns1.domain.com) and need glue records at the parent registry so resolvers can find them. External zone delegation uses NS records in your existing zone file to hand authority for a subdomain (such as app.domain.com) to a different DNS provider.
Two Different Layers of DNS
Child nameservers are authoritative self-hosting. You run the DNS servers, name them under your own domain, and register their IP addresses at the registry. Zone delegation is an administrative handoff. You keep your nameservers and add NS records that give another provider authority over one subdomain.
Child nameservers | Zone delegation | |
Scope | The whole domain | One subdomain and everything beneath it |
Configured at | Registrar, published by the registry | Your own zone file |
Glue needed | Yes, for in-domain names | Only if the NS hostnames sit inside the delegated subdomain |
When to Use Child Nameservers
Choose them when you operate DNS infrastructure under your own brand: white-labeled hosting, private BIND or PowerDNS servers, or reselling hosting so customers see ns1.yourbrand.com instead of a third party. You need at least two server IPs and DNS software already running on them.
When to Use Zone Delegation
Choose it when someone else should control one subdomain without touching the rest of your domain. You can hand cloud.company.com to AWS Route 53 or Azure DNS, so their team manages everything beneath it while your root zone, website, and email stay untouched. Most such delegations point to the provider's own nameserver hostnames, which sit outside your zone and need no glue.
The Registry Dependency
This is the boundary. Child nameservers are registered with the parent TLD registry, which publishes their addresses as glue so resolvers can reach them without a circular lookup. Zone delegation lives entirely inside your own zone file as NS records for the subdomain, and the registry never sees it. Glue appears here only when the delegated nameservers are named inside the subdomain itself, and then those address records live in your zone.
Common Configuration Errors
Registering child nameservers to delegate a subdomain: Registering a host at the registry only publishes a nameserver's address. It doesn't hand cloud.company.com to anyone. That takes NS records in the parent zone.
Changing the domain's nameservers to hand off one subdomain: Nameservers set at the registrar apply to the entire domain. Pointing them at a client's server hands over your website and email too.
Leaving old records at the delegation point: Records at or below a delegated name stop being authoritative in your zone, so they quietly stop working.
What This Means for You
NameSilo handles the child nameserver side directly. In Domain Manager, click the blue globe icon, scroll to Registered Name Servers, click Manage, and add each host with its IP address. Then point your domains at them through the NameServer Manager.
Subdomain NS delegation is different. NameSilo's DNS Manager supports record types like A, AAAA, CNAME, MX, TXT, and SRV, but not NS records for subdomains. To delegate a subdomain, host your zone with a DNS provider that supports NS delegation and keep NameSilo as your registrar. Or point the subdomain at the client's server with an A or CNAME record, which shares the destination without sharing DNS control. Search available names to get started.
Frequently Asked Questions
What is a child nameserver?
A nameserver under your own domain, like ns1.yourdomain.com, registered with its IP at the registry.
What is DNS zone delegation?
Handing authority for a subdomain to other nameservers using NS records in the parent zone.
When do I need a glue record?
Only when a nameserver's hostname sits inside the zone it serves.
Can a subdomain have different nameservers than the root domain?
Yes, through NS delegation, if your DNS host supports it.
How do I delegate a subdomain to another DNS provider?
Add NS records for the subdomain in the parent zone pointing to the provider's nameservers.
What is the difference between an NS record and a glue record?
NS names the authoritative servers. Glue supplies their IP addresses when needed.
Why are child nameservers used by web hosts?
They let hosts show branded nameservers like ns1.host.com on every customer domain.
How do I configure zone delegation at NameSilo?
NameSilo's DNS Manager doesn't support subdomain NS records, so use a DNS host that does.
NameSilo Staff
The NameSilo staff of writers worked together on this post. It was a combination of efforts from our passionate writers that produce content to educate and provide insights for all our readers.
