Windows Server 2022 – Asymmetric routing causing intermittent packet loss – 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

TCP sessions reset or stall under load because return traffic follows different paths with policy mismatch.

Environment & Reproduction

Observed in multi-homed servers with mixed static and dynamic route sources.

Get-NetRoute
Get-NetIPInterface
Test-NetConnection appgw.corp.local -Port 443

Root Cause Analysis

Unequal metrics, stale next-hop routes, and policy-based routing on adjacent devices create asymmetric flows.

Quick Triage

Identify duplicate destination prefixes and route metrics.

Get-NetRoute | Group DestinationPrefix | Where-Object Count -gt 1
Get-NetIPInterface | Sort InterfaceMetric

Step-by-Step Diagnosis

Trace path behavior and correlate with interface counters.

tracert appgw.corp.local
pathping appgw.corp.local
Get-NetAdapterStatistics

Solution – Primary Fix

Normalize route metrics and pin preferred egress paths.

Set-NetIPInterface -InterfaceAlias 'Ethernet0' -InterfaceMetric 10
Set-NetIPInterface -InterfaceAlias 'Ethernet1' -InterfaceMetric 50
New-NetRoute -DestinationPrefix 10.80.0.0/16 -NextHop 10.0.0.1 -InterfaceAlias Ethernet0 -PolicyStore PersistentStore

Solution – Alternative Approaches

Use host firewall stateful allowances and upstream route policy correction.

Get-NetFirewallProfile
Get-NetRoute -PolicyStore PersistentStore

Verification & Acceptance Criteria

Round-trip path is stable and packet loss remains within baseline.

pathping appgw.corp.local
Get-NetRoute
Get-NetAdapterStatistics

Rollback Plan

Restore previous interface metrics and remove new persistent routes.

Set-NetIPInterface -InterfaceAlias 'Ethernet0' -InterfaceMetric 25
Remove-NetRoute -DestinationPrefix 10.80.0.0/16 -Confirm:$false

Prevention & Hardening

Maintain route-policy source of truth and validate after network topology changes.

Get-NetIPInterface | Export-Csv interface-metrics.csv -NoTypeInformation

Related Errors & Cross-Refs

Commonly coexists with DNS timeout symptoms and firewall state tracking anomalies.

Related tutorial: View the step-by-step tutorial for Windows Server 2022.

View all Windows Server 2022 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Microsoft Learn: TCP/IP routing, interface metrics, and path diagnostics.