How do I handle the issue of slow connection establishment after I configure Anti-DDoS IP?

Problem description

After you configure Anti-DDoS IP, it is slow to establish connections.

Cause

This issue is caused by the new Explicit Congestion Notification (ECN) feature introduced in Windows Server 2012.

Solution

1. Log on to the ECC instance.
2. Run Command Prompt as an administrator and disable ECN.
   netsh int tcp set global ecncapability=disabled