Linkedin.com with D-Link DSL-520T Routers.

Today my boss asked me why did he cannot accept the invitation of his friend on 'linkedin.com'. And I said to him that I had no account on linkedin.com, I would make one and see what's causing the problem.

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 :

1. $telnet
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 FORWARD
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

6. Find and delete the this line :

TCPMSS tcp -- 0.0.0.0/0 0.0.0.0/0 tcp flags:0x06/0x02 TCPMSS set 1360

Using 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.

Good Luck.

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1 Litre of Tears... More than just a movie...

I never thought that my life would be affected so much by a movie, but it does. '1 Litre of Tears', that's the title of the movie that makes me realize what's the meaning of live and how to be a better man.

The movie was based on a true story about a girl named Kitou Aya. She got a disease called Spinocereberral Degeneration Disease and until now there's no known cure for this cruel disease. This disease makes a person to slowly lose control over his body, every basic human abilities. And this girl, who was 15th years old when she got this disease, fought for her life and still try to help others until the very last moment of her life.

At the first time she got this disease, she did not have any reason to live, cause she felt that she was only waited for her time. But after that, she had found the meaning of life because of this disease too. And she shared about what she had found to everyone through her diary.

This movie shared many of Aya's thought about live and how she faced her 'world' after she got that disease. On of her words that influence me so much was:

People shouldn't dwell on the past. It's enough to try your best in all that you're doing now.

Only by a simple words like this, I was realize that I must go on and I realize that past failures should make better next time.

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