Webstart Workstation connection refused

Products

• APP PERF MANAGEMENT
• CA Application Performance Management Agent (APM / Wily / Introscope)
• CUSTOMER EXPERIENCE MANAGER
• INTROSCOPE

Issue/Introduction

Webstart Workstation gets "Connection Refused" when connects to MOM.

Webstart Workstation connects to  Collector EMs without any issue.

Webview connects to MOM without any problem. 

Cause

Possible causes: 

1. connectivity
2. Port
3. firewall
4. proxy
5. DNS

Environment

CA APM 10.7 SP3
RHEL 6.0

Resolution

1. Make sure the computer can ping telnet using the same port
2. Check the firewall 
3. Make sure the Proxy settings 
4. Check any changes on the DNS