After sign up process I was asked to confirm via email, and when process start, the confirmation page couldn't load at all. It was because the confirmation page was using HTTPS, and some how only 'https://www.linkedin.com'' that cannot load. Other 'https' pages was load without any problem.
After googling for about an hour, I've found that my router which is D-Link 520T has a default firewall rules that change the TCPMSS. Now I don't want to explain what is TCPMSS, but that was the cause why https://www.linkedin.com page could not be loaded.
I login to the router using my linux box. This is how to do i :
2. Login using the same account as the web interface.
3. then you had the root shell of the D-Link router.
4. #iptables -L FORWARD (remember that Linux IS case sensitive.)
5. You will see something like this
#iptables -L FORWARD6. Find and delete the this line :
Chain FORWARD (policy ACCEPT)
target prot opt source destination
TCPMSS tcp -- 0.0.0.0/0 0.0.0.0/0 tcp flags:0x06/0x02 TCPMSS set 1360
ACCEPT all -- 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED
DROP tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:23
DROP tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:21
DROP tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:20
ACCEPT udp -- 0.0.0.0/0 0.0.0.0/0 udp dpt:500
DROP tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:53
DROP udp -- 0.0.0.0/0 0.0.0.0/0 udp dpt:53
DROP udp -- 0.0.0.0/0 0.0.0.0/0 udp dpt:67
DROP udp -- 0.0.0.0/0 0.0.0.0/0 udp dpt:520
ACCEPT 2 -- 0.0.0.0/0 0.0.0.0/0
DROP icmp -- 0.0.0.0/0 0.0.0.0/0 icmp type 8 state NEW
DROP all -- 0.0.0.0/0 0.0.0.0/0
TCPMSS tcp -- 0.0.0.0/0 0.0.0.0/0 tcp flags:0x06/0x02 TCPMSS set 1360Using command :
#iptables -D FORWARD
on the example above.
#iptables -D FORWARD 1
7. Try to login to linkedin.com and it will load without problem.
There's still one problem, this is my prediction only, but the firewall rules will be reset everytime the router restart. This mean that we have to do it everytime after the router is restarted.