Computer Forums

Member Login

Remember Me? Sign Up! | Forgot Password
 
Slogan
 
Closed Thread
Old 09-23-2006, 11:44 AM   #1 (permalink)
 
Super Techie

Join Date: Jul 2004

Posts: 398

kostas

Default Can't access a website

Using Ubuntu Dapper, and Firefox I can't access the site www.contra.gr

I've tried other browsers and it doesn't work.

Pinging it works fine but a tracepath stops at the 14th hop and then nothing.

Other computers work fine on the same LAN.

The HOSTS file is clear.

What else can I try?
__________________

kostas is offline  
Old 09-23-2006, 11:47 AM   #2 (permalink)
 
Master Techie

Join Date: Apr 2004

Posts: 2,534

horndude is on a distinguished road

Default

check the resolv.conf file and make sure dns numbers are present

as root run the route command w/o any options, make sure the routing table is correct
horndude is offline  
Old 09-23-2006, 11:56 AM   #3 (permalink)
 
Super Techie

Join Date: Jul 2004

Posts: 398

kostas

Default

DNS is fine.

Route table looks thin...

Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
localnet * 255.255.255.0 U 0 0 0 eth0
default home 0.0.0.0 UG 0 0 0 eth0

__________________

kostas is offline  
Old 09-23-2006, 12:07 PM   #4 (permalink)
Law
Law's Avatar
 
Wizard Techie

Join Date: Aug 2005

Location: the data closet

Posts: 4,172

Law is on a distinguished road

Default

So you can ping www.contra.gr and get a reply? But you can't access it through a web browser?
Law is offline  
Old 09-23-2006, 12:17 PM   #5 (permalink)
 
Super Techie

Join Date: Jul 2004

Posts: 398

kostas

Default

correct.

PING contra.gr (89.234.32.242) 56(84) bytes of data.
64 bytes from migration1.contra.gr (89.234.32.242): icmp_seq=1 ttl=114 time=109 ms
64 bytes from migration1.contra.gr (89.234.32.242): icmp_seq=2 ttl=114 time=111 ms
64 bytes from migration1.contra.gr (89.234.32.242): icmp_seq=3 ttl=114 time=108 ms
64 bytes from migration1.contra.gr (89.234.32.242): icmp_seq=4 ttl=114 time=186 ms
64 bytes from migration1.contra.gr (89.234.32.242): icmp_seq=5 ttl=114 time=106 ms
64 bytes from migration1.contra.gr (89.234.32.242): icmp_seq=6 ttl=114 time=121 ms
64 bytes from migration1.contra.gr (89.234.32.242): icmp_seq=7 ttl=114 time=106 ms

--- contra.gr ping statistics ---
7 packets transmitted, 7 received, 0% packet loss, time 7406ms
rtt min/avg/max/mdev = 106.661/121.626/186.644/26.968 ms

__________________

kostas is offline  
Old 09-23-2006, 12:49 PM   #6 (permalink)
Law
Law's Avatar
 
Wizard Techie

Join Date: Aug 2005

Location: the data closet

Posts: 4,172

Law is on a distinguished road

Default

It's an application problem, more likely a firewall or the browser setting. Does Ubuntu have a firewall enable, not sure about it since I don't use it.

Things to check are the proxy setting, if you configure the Ubuntu to connect to a proxy server, that's one of the reason why you can ping but can't use the browser.

Browser setting may inherit the proxy setting. Check the options. Firefox options should be in edit>preference>general tab>connection settings
Law is offline  
Old 09-23-2006, 12:53 PM   #7 (permalink)
 
Super Techie

Join Date: Jul 2004

Posts: 398

kostas

Default

No, I'm sure I'm not using a proxy to connect. There's a firewall enabled but disabling it still gives me the same results. Also, here's what Ethereal caught while trying to connect to the site:


__________________

kostas is offline  
Old 09-23-2006, 01:31 PM   #8 (permalink)
Law
Law's Avatar
 
Wizard Techie

Join Date: Aug 2005

Location: the data closet

Posts: 4,172

Law is on a distinguished road

Default

Disable the firewall and make sure it doesn't start during reboot, now reboot your machine and see what happens.

I'm not an expert or anything at analyzing packets, but what you're showing me is a TCP three-way handshake gone wrong.

From the second and third packet: The second packet which is the server respond with it's sequence and maximum segment size to your computer, then the third is the same thing, but look at the time between the second and the third. That mean there was a delay and the web server initiated a second transmission because it didn't get an acknowledgment from your computer. Then the fourth, that's your computer trying to respond to the web server that it didn't receive an respond and to redo the handshake again. If you can't communicate with the web server, it's going to be like that forever. This sounds a lot like a firewall problem.

I'm not that good at analyzing packets yet, but that's just something I believe is going on.
Law is offline  
Old 09-23-2006, 01:42 PM   #9 (permalink)
 
Super Techie

Join Date: Jul 2004

Posts: 398

kostas

Default

i'm thinking of lowering the mtu to 1380 to see if that's gonna help.
__________________

kostas is offline  
Old 09-23-2006, 03:36 PM   #10 (permalink)
Law
Law's Avatar
 
Wizard Techie

Join Date: Aug 2005

Location: the data closet

Posts: 4,172

Law is on a distinguished road

Default

I doubt changing the MTU is going to help.

Is it only with this web site? and it's only with your computer on Linux? If you dual boot, would Windows be able to access the web site?
Law is offline  
 
Closed Thread

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On