A lame delegation happens when a parent zone lists a nameserver for your domain in its NS records, but that server does not actually hold or serve your zone authoritatively. The server may be down, misconfigured, or no longer controlled by you.
Why it matters
Resolvers pick among the listed nameservers. When they hit a lame one, they must time out or move on, which adds delay or causes intermittent SERVFAIL for part of your users. It often appears after switching DNS providers without updating the registrar, or after a provider deletes a zone. A lame delegation to a name in a domain someone else can register is also a hijacking risk.
Example
Compare the parent's NS list with what each server says:
dig +short NS example.com
dig @ns1.old-provider.net example.com SOA +norecurseIf the second query returns no aa (authoritative answer) flag or a REFUSED status, that server is lame for your zone. Update the nameservers at the registrar, or recreate the zone at that provider.
Common mistakes
- Changing DNS hosting but leaving an old nameserver in the registrar list.
- Leaving a delegation pointing at a provider after cancelling the account.
- Testing only through a caching resolver, which hides one broken server.
Related
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This page is general information written by our editorial team and updated when documentation changes. Servers and providers differ, so test changes safely first. See our editorial policy and disclaimer.