cannot acces a particular website

igadoter · 11-29-2010, 05:30 PM

Hi,
I have met following problem: there is a website I cannot access.
When I am trying to connect to this site I get an error message. I tried all browsers installed on my system. Seamonkey, Firefox, Konqueror. All failed. I don't understand this completely as I have no problem with connecting to internet. Now I am thinking that I myself somehow unintentionally blocked an access to this particular site. Is it possible? Under W$ I have no problems at all.

unSpawn · 11-29-2010, 06:26 PM

Quote:

Originally Posted by igadoter

When I am trying to connect to this site I get an error message.

Talking about an error message does not equal posting the exact error message.

jefro · 11-29-2010, 08:31 PM

nslookup that web page and see what ip returns. Go to a working computer and do same.

igadoter · 11-30-2010, 12:37 AM

Quote:

Originally Posted by unSpawn

Talking about an error message does not equal posting the exact error message.

This is an error message from Seamonkey

Code:

The connection was refused when attempting to contact www.im.pwr.wroc.pl
Though the site seems valid, the browser was unable to establish a connection.

igadoter · 11-30-2010, 12:39 AM

Quote:

Originally Posted by jefro

nslookup that web page and see what ip returns. Go to a working computer and do same.

Here

Code:

piotr@(none):~$ nslookup www.im.pwr.wroc.pl
Server:         192.168.1.100
Address:        192.168.1.100#53

Non-authoritative answer:
www.im.pwr.wroc.pl      canonical name = alfa.im.pwr.wroc.pl.
Name:   alfa.im.pwr.wroc.pl
Address: 156.17.7.2

At this at hand I have only W$ workin and no idea how-to 'nslookup' under W$. But in an office I have a computer with installed Debian. Which I am sure works well.

unSpawn · 11-30-2010, 09:46 AM

What does 'curl -v http://www.im.pwr.wroc.pl/' return? And 'curl -v http://156.17.7.2/' return?

igadoter · 11-30-2010, 05:46 PM

Quote:

Originally Posted by unSpawn

What does 'curl -v http://www.im.pwr.wroc.pl/' return? And 'curl -v http://156.17.7.2/' return?

Both forms give the same answer

Code:

piotr@(none):~$ curl -v http://www.im.pwr.wroc.pl/
* About to connect() to www.im.pwr.wroc.pl port 80 (#0)
*   Trying 156.17.7.2... No route to host
* couldn't connect to host
* Closing connection #0
curl: (7) couldn't connect to host

It is the same when I try to an ssh connection.

unSpawn · 11-30-2010, 07:12 PM

For me using traceroutes from around the globe (traceroute.org), including Poland, show no routing problems into .gov.pl / .wroc.pl and curl shows me the page.
Resolving the host address shows there's no DNS problem on your end but HTTP and SSH (TCP) fail. Sure smells like a filter to me.
Can you 'tcptraceroute' (or 'lft' with "-vbE") the address and port TCP/80?

jefro · 11-30-2010, 07:26 PM

nslookup in MS is the very same.

Now lookup whois then to find out the ip or name and see if it is correct. Could try the ip address in the browser but that would normally be useless since it might be host headers but do it just to see.

igadoter · 11-30-2010, 08:23 PM

Quote:

Originally Posted by unSpawn

Can you 'tcptraceroute' (or 'lft' with "-vbE") the address and port TCP/80?

Have no 'tcptraceroute' command but have this

Code:

root@(none):~# traceroute -p 80 www.im.pwr.wroc.pl
traceroute to alfa.im.pwr.wroc.pl (156.17.7.2), 30 hops max, 38 byte packets
 1  156.17.7.197 (156.17.7.197)  3000.874 ms !H  3003.615 ms !H  3003.977 ms !H

igadoter · 11-30-2010, 08:36 PM

Quote:

Originally Posted by jefro

Now lookup whois then to find out the ip or name and see if it is correct.

How to properly issue this command? When I tried "whois www.im.pwr.wroc.pl" or 'whois alfa.im.pwr.wroc.pl' I get nothing. But if 'whois 156.17.7.2' then I get

Code:

NetRange:       156.17.0.0 - 156.18.255.255
CIDR:           156.18.0.0/16, 156.17.0.0/16
OriginAS:
NetName:        RIPE-ERX-156-17-0-0
NetHandle:      NET-156-17-0-0-1
Parent:         NET-156-0-0-0-0
NetType:        Early Registrations, Transferred to RIPE NCC
Comment:        These addresses have been further assigned to users in
Comment:        the RIPE NCC region.  Contact information can be found in
Comment:        the RIPE database at http://www.ripe.net/whois
...

and much more additional information.

unSpawn · 12-01-2010, 01:02 AM

Quote:

Originally Posted by igadoter

Code:

1  156.17.7.197

So your first hop places you inside the destination 156.17.0.0/16 net...
How about asking the Wroclawska Akademicka Siec Komputerowa helpdesk?

igadoter · 12-01-2010, 02:56 AM

Quote:

Originally Posted by unSpawn

So your first hop places you inside the destination 156.17.0.0/16 net...
How about asking the Wroclawska Akademicka Siec Komputerowa helpdesk?

Thank's. Very good idea. I'll do that.