Agent is unable to connect to NS

Products

• Client Management Suite
• IT Management Suite

Issue/Introduction

Suddenly some of the Agents are failing to connect to the Notification Server.

Notification Server allows both HTTP and HTTPS (and all TLS versions)

From the Agent machine using IE, http://{notificationserver}/Altirs/ can be accessed just fine.

Some other Agents are successfully communicating with the Notification Server.

Environment

Release : 8.5

Component :

Cause

Network Issue.

 

Resolution

Capturing network packet shows the HEAD request was sent to http://{notificationserver}/altiris/NS/Agent/PostEvent.asp?xxxxx
At the network layer, there was no [ACK] being returned so the [TCP Retransmission] was performed 5 times but still failed and the client closed the connection.

This only happens when accessing any notification server URL other than /altiris/ so the network policy need to be reviewed by customer's network team.