Endpoint Protection

All,

We have SEP MR4-MP2 deployed in most of our offices and recently we noticed an issue with huge network degradation on some of our laptops using wireless.  The issue appears to be related to 802.11n and disappears once we disable Network Threat Protections.  In testing I found that RU5 fixed the issue on several clients.  At this stage I am try to determine what is the root cause of the issue is and was wondering is anyone has come across this issue already and found the cause.

According to our networking guys assisting with this the laptops are seeing heavy packetloss (40-50%) and were already running the latest Intel 12.4 client. Continued investigation lead them to disable SEP, which resolves the issues immediately. SEP running – packetloss, SEP not running – no packetloss.

At this stage we are not in a position to upgrade our entire company to SEP RU5, so I need to determine what is causing the issue and right now the main culprit appears to be SEP.

Thanks,
Jeff

Try to upgrade the drivers of NIC and see if that helps

Well I don't know if this will help or not but RU5 is out now and one of the "fixes" is:

With NICs that use a TCP offload engine, Symantec Endpoint Protection with Network Threat Protection enabled causes networking problems, such as connection failures and performance degradation
Fix ID: 1389258
Symptom: Teefer2 causes packet loss with TCP/UDP checksum offload by not preserving checksum data.
Solution: Teefer2 corrected to preserve checksum data.

The reason I say "fixes" is because this issue was also supposed to be fixed in MR4-MP2 and can also be found in the MR4-MP2 fixes section. It might be that they fixed it in MR4-MP2 but it was still happening in certain cases  so they fixed it again with RU5. I might suggest that you upgrade a test workstation to see if you still see the packet loss on RU5.

Hope this helps
Grant

Check this as well. Its a fix in the latest RU5 version.

DNS resolution fails while connected via Microsoft VPN
Fix ID: 1442277
Symptom: Teefer2 causes packet loss with TCP/UDP checksum offload by not preserving checksum data.
Solution: Teefer2 corrected to preserve checksum data.