Microsoft Exchange 2019 Edge : Test‑EdgeSynchronization: Normal Mode vs FullCompareMode

 


Understanding the Right Tool for Microsoft Exchange 2019 Edge Transport Troubleshooting

Test‑EdgeSynchronization: Normal Mode vs FullCompareMode

In Exchange environments that use an Edge Transport server, EdgeSync plays a critical role in ensuring accurate and secure mail flow. Administrators frequently use the Test-EdgeSynchronization cmdlet to validate EdgeSync health.

However, confusion often arises around the difference between Normal mode and FullCompareMode. This document explains how both modes work, what they test internally, and when each should be used.


What Is EdgeSync?

EdgeSync is the process by which Mailbox servers push configuration and recipient routing data to the Edge Transport server.

Important characteristics:

  • Edge servers do not join Active Directory
  • Data is stored locally in AD Lightweight Directory Services (AD LDS)
  • Synchronization occurs over secure LDAP (TCP port 50636)

EdgeSync consists of two synchronization cycles:

  • Configuration synchronization – runs every 1 minute
  • Recipient synchronization – runs every 5 minutes

Test‑EdgeSynchronization (Normal Mode)

Normal mode is a health and connectivity validation test.
It answers the question:

“Can EdgeSync run successfully?”

PowerShell Command

Test-EdgeSynchronization

What Normal Mode Checks

  • Edge subscription existence
  • Secure LDAP connectivity to Edge (TCP 50636)
  • Certificate‑based authentication
  • Ability to execute:
    • Configuration synchronization
    • Recipient synchronization

What Normal Mode Does NOT Check

  • No comparison between Active Directory and Edge AD LDS
  • No validation of recipient or connector data accuracy
  • No detection of silent data drift

Normal mode can return Success even when Edge data is incomplete or incorrect.

When to Use Normal Mode

Use Normal mode for:

  • Daily or routine health checks
  • After restarting Exchange transport services
  • After firewall or certificate changes
  • After creating or renewing an Edge subscription
  • Validations during business hours

It is fast, low‑impact, and safe to run frequently.


Test‑EdgeSynchronization – FullCompareMode

FullCompareMode is a deep integrity validation test.
It answers the question:

“Is EdgeSync data correct and in sync with Active Directory?”

PowerShell Command

Test-EdgeSynchronization -FullCompareMode

What FullCompareMode Checks

Everything in Normal mode plus:

  • Object‑by‑object comparison between:
    • Active Directory (Mailbox server)
    • AD LDS (Edge server)
  • Attribute‑by‑attribute validation of:
    • Accepted domains
    • Send connectors
    • Mail‑enabled users, contacts, and groups
    • ProxyAddresses
    • TargetAddress and routing attributes

FullCompareMode detects:

  • Missing recipients on Edge
  • Orphaned or stale objects
  • Attribute mismatches affecting mail routing

This mode is essential for troubleshooting issues such as:

  • 550 5.1.1 Unknown Recipient
  • Hybrid mail routing inconsistencies
  • Post‑recovery EdgeSync validation

Normal Mode vs FullCompareMode – Key Differences

Normal Mode

  • Confirms EdgeSync can run
  • Verifies connectivity and trust
  • Does not validate data correctness
  • Fast and production‑safe

FullCompareMode

  • Confirms EdgeSync data accuracy
  • Detects silent routing issues
  • Resource‑intensive
  • Best used during off‑hours

Best Practices

  • Use Normal mode for routine validation
  • Use FullCompareMode when:
    • Mail flow issues persist
    • EdgeSync errors were recently fixed
    • Bulk directory changes were made
  • Avoid running FullCompareMode frequently in large environments

Final Takeaway

  • Normal mode answers:
    “Is EdgeSync operational?”
  • FullCompareMode answers:
    “Is EdgeSync correct?”

Both are critical — but they serve different purposes.

 

Test‑EdgeSynchronization: Normal Mode vs FullCompareMode

Comparison Table

Category

Normal Mode

FullCompareMode

PowerShell Command

Test-EdgeSynchronization

Test-EdgeSynchronization -FullCompareMode

Primary Purpose

Validates EdgeSync health and connectivity

Validates EdgeSync data accuracy and consistency

Type of Check

Operational health check

Deep integrity and correctness check

Edge Subscription Validation

Yes

Yes

LDAP Connectivity (TCP 50636)

Yes

Yes

Certificate Trust Validation

Yes

Yes

Configuration Sync Validation

Yes

Yes

Recipient Sync Validation

Yes

Yes

Object-by-Object Comparison

No

Yes

Attribute-by-Attribute Comparison

No

Yes

Accepted Domains Validation

Basic presence

Full comparison with AD

Send Connector Validation

Sync success only

Full attribute comparison

Mail-Enabled Users / Contacts

Sync success only

Full object comparison

ProxyAddresses Validation

No

Yes

TargetAddress / Routing Attributes

No

Yes

Detects Silent Data Drift

No

Yes

Detects Missing Recipients on Edge

No

Yes

Typical Use Case

Routine health checks and post-change validation

Troubleshooting mail flow or routing issues

Performance Impact

Low

Medium to High

Execution Time

Fast (seconds)

Slow (can take minutes in large orgs)

Safe During Business Hours

Yes

Not recommended

Recommended Frequency

Regular / Daily

Only when required

Typical Scenario

“Is EdgeSync running?”

“Why is mail flow still broken?”

 

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