Sequence of steps to be followed while troubleshooting Client Commuincation
Symantec Endpoint Protection: Troubleshooting Client/Server Connectivity
Testing Communication from an Endpoint Protection client to the Endpoint Protection Manager
Clients stop communicating with Symantec Endpoint Protection Manager (SEPM) with HTTP 401 error in Sylink log and HTTP 401.1 error in IIS log
Client is not appearing in Symantec Endpoint Protection Manager (SEPM), error: HTTP returns status code=407
How to Replace the sylink on the Client :
1.Copy of the file Sylink.xml from the server from C:\Program Files\Symantec\Symantec Endpoint Protection Manager\data\outbox\agent\
2. On the client computer , click Start > Run, type smc -stop, and click OK.
3. Copy the Sylink.xml into the C:\Program Files\Symantec\Symantec Endpoint Protection folder, and replace any existing Sylink.xml file.
4. Click Start > Run, type smc -start, and click OK.
Steps to edit the SYSTEM account proxy settings through using a Scheduled Task:
Click Start > Run
Type cmd and click OK
Type in this the following command and press Enter:
at 12:00 /INTERACTIVE "C:\Program Files\Internet Explorer\iexplore.exe"
You should receive a confirmation stating "added a new job..."
Navigate to the Control Panel and open Scheduled Tasks
Right-click the new task just created in the previous step (probably named "At1") and click Run.
This will open an Internet Explorer window that will now be running under the SYSTEM account.
Go to the Tools menu and select Internet Options
Select the Connections tab and click the LAN Settings button.
Uncheck Use a proxy server for your LAN
Click OK twice
Click Start > Run
Type SMC -stop and click OK.
The Symantec Endpoint Protection icon should disappear from the system tray.
Click Start > Run
Type in SMC -start and click OK.
How to get Sylink log:
How to enable Sylink Debugging for Symantec Endpoint Protection (SEP) in the registry