Internet Access problem via LAN connection through web proxy

Problem description

I was using Mountain Lion OS X 10.8 and recently I have upgraded my Mac with new version of OS X Yosemite (version 10.10). Now unable to access internet via proxy but with wifi still I can access internet without any problem (without proxy) whereas in previous version without any problem I was
access internet with same settings which I am using now. I have checked with my network admin and got to know: none of the traffic from my Mac is reaching
proxy server. Conclusion is after setup proxy setting in Mac machine cannot be create any out bound traffic. Means, It’s not passing through. I have included
my network admin resolution for reference.

According to our analysis during the remote session please note the following:

_Packet Capture and log from the proxy side do not show any traffic from the MAC OS machine.
_Packet Capture on the MAC laptop itself also shows that the traffic is not being directed to the proxy even though the proxy is well configured.
Therefore the problem you are facing with Yosemite OS seems to be related to the global proxy configuration, and has nothing to do with Bluecoat proxy
itself since the traffic is not reaching it.

My Mac Book Pro Spec

Mac Book Pro 17-inch Mid 2010

Processor 2.53 Intel Core i5

Memory 4GB 1067 MHz DDR3

Previous OS version OS X 10.8(12A269) Mountain Lion

Can anyone help me
regarding this issue?