Web browsing - strange behaviour.. Please help

[syscode]

Am new, very new, to ubuntu... Installed ubuntu 8.04 last night and this
problem wouldn't go..

All seems well in terms of internet connection, IM chat is fine, DNS and
ping are fine -
apart from firefox only able to connect with a few sites..

I can get google.com for example - but not ubuntu.com. I am able to got
connected with: diamondcard.us (ekiga), and the bbc (front page and weather
- but not news..)

After a bit of a search on the ubuntu help site, it seemed that maybe my
problem was solvable by adding the line
net.ipv4.tcp_default_window_scaling = 0
to etc/sysctl.conf

I added the line to the top of the file - but it didn't make any
difference.

Any idea what may cause this behaviour and how to fix it..?

Not sure if relevant:

The machine is dual boot.
Internet connection is via ethernet cable to a router.


Many thanks!

(I really like ubuntu - please help kick XP off my box..)


This is a rewarding/update on a post from yesterday:
http://ubuntuforums.org/showthread.php?t=854842

[ModelM]

On the sites you cannot reach, are you getting a 404 error or what?

Are you connecting via ppp dialup, or are you connecting through a wired/wireless network card to a DSL or cable modem?

[syscode]

Good points, ModelM.

Yes, I forgot to mention that the connection is an ethernet cable to a router.

The browser keeps trying to load the sites.. I haven't noticed any 404s, but either timed out messages, or that it just keeps trying to load..

[ModelM]

The first thing I'd try is a different browser, and I mean *really* different. I'd try an ascii browser. I think w3m is included in the stock install, or you could install links or, my favorite, lynx.

Lynx has no scripting, java, flash, or any other foo-foo. It's just a browser. If it can load a site your other browser can't, that's a pretty good clue...

[superprash2003]

ping the sites which arent loading and get the site's ip and enter the ip in firefox or whatever browser you use.. and if the webpage opens, then it could be a dns issue . so you could try changing to opendns servers . their ips are 208.67.222.222 and 208.67.220.220 .. if you still face problems, then you could try changing MTU values

[syscode]

ModelM thanks for the suggestion.

I tried to load lynx, but had to download it via the app installer - but that showed that it couldn't connect to server. Same case happend with epiphany.

Therefore I conclude that despite the fact I can ping sites and see my DNS details, something IS more fundamentaly wrong with my internet connection on ubuntu..

Indeed, going to network tools / devices / ethernet interface (eth0) / configure - gave me "the interface doesnot exist Check that it is correctly typed and that it is correctly supported by your system"..

So Maybe its my Ethernet interface?

I searched for possible solutions here, got:
http://ubuntuforums.org/showthread.p...thernet&page=2 as the nearest possible problem to main.

However, since ipconfig on XP shows:
Dhcp Enabled. . . . . . . . . . . : Yes
It seems I am not on a bridged mode..

superprash2003, Thanks! - per above, and that attempting to use ip didn't bring sites up, maybe its another indicator I need to know whats wrong with the detection of my ethernet cable..

BTW, what is MTU..?


Hope someone can help, though maybe I should really open another, new issue..

Cheers!

[superprash2003]

regarding MTU, you could try this http://prash-babu.blogspot.com/2008/...-in-linux.html

[syscode]

The tutorial looks promising, superprash2003 - thanks!

Only thing is that interfaces document is empty..(!!)

I did the ifconfig and know the system looks for eth0.

Should I just type in that document:
iface eth0 inet dhcp
mtu 1492
???

Thanks!

[syscode]

OOOOOps!!! Sorry.. I did a typo..

Wrote gedit etc/network/ instead of gedit /etc/network/

Will try this fix idea now..

[syscode]

OK.. I have now tried all the MTU number options, and no joy..

In case its of any relevance, my interfaces file looks like:
auto lo
iface lo inet loopback
iface eth0 inet dhcp
mtu 1452
auto eth0

Maybe its something else to do with Ethernet interface error I get..?