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What I Did When Gmail Failed to Load on Any Browser

I use Chrome and FireFox sparingly in Ubuntu to login into Gmail to manage my emails. I may ignore phone calls or SMS, but I do entertain emails at least once a day. My computer is always connected to the Internet and I seldom turn it off. Last few days Gmail ceased to load on any of the browsers in my Ubuntu computer. However, Gmail did load on the other two Windows computers on the same LAN. It did so as well on an Android phone connected to the same LAN. Obviously it was an Ubuntu problem, or something was wrong with my computer that run Ubuntu. Unfortunately I had only one computer that ran Ubuntu when the problem happened so I could not certainly confirm that it was indeed an Ubuntu problem. It could not be a hardware problem because I still can browse other websites.

This was the error message I got from the browser:

Error 324 (net::ERR_EMPTY_RESPONSE): Unknown error

'Unknown error' is a very bad error message. If the browser didn't know what went wrong then it must be a low level communication error which was underneath the HTTP, TCP/IP or other Internet protocols. There was a theory that the problem had something to do with ISP. In fact, somebody even changed ISP. If you don't believe me, go google the error message. I tend to believe with the theory because my ISP had just finished a maintenance work. But then why my Windows computers hadn't had similar problem? On the other hand my Internet connection was not totally out.

I was looking at the computer network settings when I noticed the MTU had some figure that I could manipulate. The MTU for the network card was set to 1500 which was the maximum for Ethernet. I lowered it to 1000 and it instantly cleared the nasty problem. But I had just given up 30% of the network performance. So I raised it to 1400 and it worked better. I tried 1492 and 1430 but both didn't work so I settled on 1400.

Here how I set it on Ubuntu. I edited the following file...

/etc/network/interfaces

...to add these lines...

auto eth0
iface eth0 inet dhcp
pre-up /sbin/ifconfig $IFACE mtu 1400

...and restarted the computer.

You may want to test it before restarting the computer. Run this...

sudo /etc/init.d/networking restart

...and...

ifconfig

...it will show that MTU is set to 1400.

I would like to classify this problem as an Ubuntu bug which can be solved by automatically setting the MTU regressively when the problem occurs. Your ISP has their own reason whether or not to entertain you with the MTU settings.

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