Network connectivity issues

Solution:

1. Ensure the Network Interface Card (NIC) drivers are current.

2. Ensure the NIC firmware is current.

3. Ensure the NIC drivers and firmware match. NIC vendors often release drivers and firmware together and require they are updated at the same time to resolve known  issues.

4. Ensure the network switch firmware is current.

5. Event ID 2012 Source srv are often times normal and can safely be ignored. Refer to the Additional Information section of this article for further details.

6. Disable TCP/IP Offload Engine (TOE) in the NIC vendor software.

7. Disable Receive Side Scaling (RSS) in the NIC vendor software.

8. Disable Large Send Offload (LSO) in the NIC vendor software.

9. Disable the following using an elevated Command Prompt.

     a. Press the Windows Logo+R, type runas /user:administrator@domain.local cmd where domain.local is replaced by the name of the Active Directory domain or local server name and press Enter. The same task can be accomplished using the Command Prompt and Run as Administrator.

     b. Type the Administrator account password when prompted and press Enter. 

     c. Type netsh int tcp set global rss=disabled and press Enter. 

     d. Type netsh int tcp set global netdma=disabled and press Enter.

     e. Type netsh int tcp set global chimney=disabled and press Enter.

     f. Type netsh int tcp set global autotuninglevel=disabled and press Enter.

     g. Type netsh int tcp set global congestionprovider=none and press Enter.

     h. Reboot the server.

          


 

Additional Information:

This information applies to Windows Server 2008, Windows Server 2008 R2, Windows Server 2012 and Windows Server 2012 R2.

Event ID 2012 Source srv can occur for many reasons some of which are completely normal. Some examples of normal conditions are below.

•      Heavy network congestion during peak times.
•      Older Windows server and client operating systems using older versions of SMB with newer versions of Windows server.
•      Unix or Apple server and client computers in the environment using older versions of SMB with newer versions of Windows server.
•      Server or client computers using redirected folders disconnecting improperly from a server due to unsuspected shutdowns or restarts.
•      Keep in mind this is a Warning in the event log, not an Error. Occasional Event ID 2012 Source srv are normal. The only time these warnings should be a cause for concern is when they occur frequently, at all times throughout the day and there are many warnings logged in succession. For example, while reviewing the System event log there are 20-30 Event ID 2012 Source Srv logged hourly throughout the day.

Event ID 2012 is logged in the System event log.

Log Name: System
Source: srv
Date: 12.08.2013 11:23:04
Event ID: 2012
Task Category: None
Level: Warning
Keywords: Classic
User: N/A
Computer: server.domain.com
Description:
While transmitting or receiving data, the server encountered a network error. Occasional errors are expected, but large amounts of these indicate a possible error in your network configuration. The error status code is contained within the returned data (formatted as Words) and may point you towards the problem.