Quick troubleshooting view
The DNS solver returns SERVFAIL instead of,an answer or,an NXDOMAIN.
- DNSSEC
- Improper delegation
- Authoritarian waiter unavailable
- Compare multiple solvers
- Check delegation
- Control DNSSEC
- Correct delegation or area
- Correct DNSSEC
- Restore Authoritative/Agent Servers
Contextual technician plan
Test an internal solver and an audience depending on the domain.
Resolve-Dns(1) example.frThe command should complete without an unexpected error and return data consistent with the intended service.
If the result is normal, keep this layer lower in the hypothesis ranking and continue with the next discriminating check.
If the result is abnormal, preserve the output and investigate this layer before making broader changes.
Control NS and Multiculturalism records.
ns Outlook example.fr 1.1.1.1The command should complete without an unexpected error and return data consistent with the intended service.
If the result is normal, keep this layer lower in the hypothesis ranking and continue with the next discriminating check.
If the result is abnormal, preserve the output and investigate this layer before making broader changes.
An incorrect DNSSEC string can cause SERVFAIL.
The exact failing name should resolve through the expected DNS server to the expected record without timeout.
If the exact name resolves correctly, compare application cache, suffix/search domain and the client or network where the failure remains.
If resolution fails or returns the wrong record, keep the queried server and answer and correct the resolver, zone/record or DNS path that is actually wrong.
Remove the correct error on the solver/authoritarian side.
The exact failing name should resolve through the expected DNS server to the expected record without timeout.
If the exact name resolves correctly, compare application cache, suffix/search domain and the client or network where the failure remains.
If resolution fails or returns the wrong record, keep the queried server and answer and correct the resolver, zone/record or DNS path that is actually wrong.
Repeat the same validation test after the correction and confirm the original symptom is gone. Validate stability before closing the incident.
Before changing configuration, record the current value and a way back.
Spend time in the city of Madrid/DNS Host if the public delegation or DNSSEC is involved.
The DNS solver returns SERVFAIL instead of,an answer or,an NXDOMAIN.
Causes probables
- DNSSEC
- Improper delegation
- Authoritarian waiter unavailable
- Zone Error
- Recursion or action problem
Diagnostic étape par étape
- 1
Compare multiple solvers
Test an internal solver and an audience depending on the domain.
- 2
Check delegation
Control NS and Multiculturalism records.
- 3
Control DNSSEC
An incorrect DNSSEC string can cause SERVFAIL.
- 4
See the DNS logs
Remove the correct error on the solver/authoritarian side.
Commands utiles
Resolve-Dns(1) example.frns Outlook example.fr 1.1.1.1Solutions possibles
- Correct delegation or area
- Correct DNSSEC
- Restore Authoritative/Agent Servers
Spend time in the city of Madrid/DNS Host if the public delegation or DNSSEC is involved.