Windows Server 2016 – HNS fails to create container network after policy changes – Fix & Prevention

📖 ~1 min read

Table of contents

1. Symptom & Impact
2. Environment & Reproduction
3. Root Cause Analysis
4. Quick Triage
5. Step-by-Step Diagnosis
6. Solution – Primary Fix
7. Solution – Alternative Approaches
8. Verification & Acceptance Criteria
9. Rollback Plan
10. Prevention & Hardening
11. Related Errors & Cross-Refs
12. References & Further Reading

Symptom & Impact

Containers fail to start because endpoint creation on NAT/transparent networks does not complete.

Environment & Reproduction

Seen after firewall, vSwitch, or policy changes impacting Host Network Service.

Get-ContainerNetwork
Get-Service hns

Root Cause Analysis

Stale HNS network objects or conflicting policy artifacts prevent endpoint provisioning.

Quick Triage

Check HNS and docker service health and enumerate existing networks.

Get-Service hns,docker
docker network ls

Step-by-Step Diagnosis

Inspect HNS operational events and stale endpoint remnants.

Get-WinEvent -LogName Microsoft-Windows-Host-Network-Service-Admin -MaxEvents 200
Get-ContainerNetwork | fl *

Solution – Primary Fix

Restart HNS, remove stale networks, and recreate required container network.

Stop-Service docker
Restart-Service hns
Start-Service docker
docker network prune -f

Solution – Alternative Approaches

Recreate the external vSwitch mapping if transparent networking cannot attach to NIC.

Verification & Acceptance Criteria

Container receives expected IP and communicates with required services.

Rollback Plan

Restore prior HNS network JSON backup and revert policy changes if connectivity regresses.

Prevention & Hardening

Apply network policy updates through staged validation on canary container hosts.

Related Errors & Cross-Refs

Can pair with vEthernet adapter ghost entries and orphaned endpoint GUID conflicts.

Related tutorial: View the step-by-step tutorial for Windows Server 2016.

View all Windows Server 2016 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Microsoft Learn: HNS architecture and Windows container network troubleshooting.