Model :

Hardware Version : Not Clear

Firmware Version :

ISP :

Hi All,

I am using WiFi router with following info.
Model No. TL-WR841N / TL-WR841ND.
Firmware Version:
3.16.9 Build 150310 Rel.54318n
Hardware Version:
WR841N v9 00000000

I am connecting my Ubuntu laptop 14.04 LTS over WiFi, I am facing one strange problem, some of the sites are not opening.
For example : https://www.codecademy.com
I am getting following error on chrome:

No data received
ERR_EMPTY_RESPONSE

And following error on firefox:

Secure Connection Failed

The connection to the server was reset while the page was loading.

The page you are trying to view cannot be shown because the authenticity of the received data could not be verified.
Please contact the website owners to inform them of this problem.

I am some experiencing package drop also when I am ping google.co.in


I tried following things :
1. reset router to default config // No use
2. Update firmware // no use
3. Change DNS to 8.8.8.8 and 8.8.4.4 // no use
4. Change DNS provide by ISP // no use


Can some help help me ?