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igadoter 11-29-2010 05:30 PM
cannot acces a particular website
 
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 (Post 4175183)
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 (Post 4175214)
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 (Post 4175306)
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 (Post 4175874)
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 (Post 4176396)
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 (Post 4176404)
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 (Post 4176447)
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 (Post 4176634)
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.


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