Telnet : Temporary failure in name resolution : Host name lookup failure

koodoo · 08-26-2005, 01:06 PM

Hi,

I am connected to the outside world via a proxy server. The I.P. of the proxy server is 10.10.11.2
I cannot telnet to a remote computer.

Here is what I am doing :

Code:

koodoo@knapsacker:~$ export http_proxy=http://10.10.11.2:8080
koodoo@knapsacker:~$ export ftp_proxy=http://10.10.11.2:8080
koodoo@knapsacker:~$ telnet drill.hackerslab.org
telnet: drill.hackerslab.org: Temporary failure in name resolution
drill.hackerslab.org: Host name lookup failure
koodoo@knapsacker:~$

I have not done any other changes anywhere.
I am currently using Slackware 10.0
I know I have to do some settings somewhere, (maybe edit some files to tell telnet where to lookup for hosts etc)

But at this point I am completely clueless

Thanks in anticipation

nixcraft · 08-26-2005, 01:42 PM

Yup you need to setup linux as dns client see by editing /etc/resolv.conf file
http://www.cyberciti.biz/nixcraft/vi...ns-client.html

koodoo · 08-26-2005, 04:25 PM

Hi,

Thanks Nixcraft for the reply and the link. I'll check it out and see if I can get telnet running.
Thanks

koodoo · 08-27-2005, 08:55 AM

Hi Nixcraft,

I read the link you gave me. It said :

Code:

1) Open /etc/resolv.conf file: vi /etc/resolv.conf 2) Add ISP nameserver as follows: search isp.com nameserver 202.54.1.110 nameserver 202.54.1.112 nameserver 202.54.1.115 Note Max. three nameserver can be used/defined at a time. 3) Test it with nslookup or dig: dig www.nixcraft.com nslookup www.nixcraft.com

This is what I know about my network :

I.P. address of the proxy server : 10.10.11.2
default gateway : 203.200.130.1
preferred dns server : 202.54.1.30

So, I believe my /etc/resolve.conf should look like this :

Code:

search isp.com  <should this be there or not ?>
nameserver 202.54.1.30

Is this right ?

I am not at my Linux box right now, so I cannot test it right now.
Thanks in anticipation.

nixcraft · 08-28-2005, 04:15 AM

Following shoud do the work:

Code:

nameserver 202.54.1.30

You need to add default gatway using command:

Code:

route add default gw 203.255.255.0 dev eth0

Btw proxy has no use to telnet as it will be used by ftp or http or https protocols only.

koodoo · 08-28-2005, 01:39 PM

Sorry, I couldn't get it to work

My /etc/resolv.conf looks like :

Code:

root@knapsacker:/home/koodoo# cat /etc/resolv.conf
nameserver 202.54.1.30
root@knapsacker:/home/koodoo#

Then I tried to execute the command "route add default gw 203.200.130.1 dev eth0" and got the following error message :

Code:

root@knapsacker:/home/koodoo# route add default gw 203.200.130.1 dev eth0
SIOCADDRT: Network is unreachable
root@knapsacker:/home/koodoo#

Now this might be because my I.P. is 10.10.27.204 (private i.p.) while that of the default gateway is 203.200.130.1 (I mean they belong to different classes of I.P.'s)

I then tried those two commands and got the following error messages :

Code:

root@knapsacker:/home/koodoo# nslookup www.nixcraft.com
Note:  nslookup is deprecated and may be removed from future releases.
Consider using the `dig' or `host' programs instead.  Run nslookup with
the `-sil[ent]' option to prevent this message from appearing.
;; connection timed out; no servers could be reached

root@knapsacker:/home/koodoo# dig www.nixcraft.com

; <<>> DiG 9.2.3 <<>> www.nixcraft.com
;; global options:  printcmd
;; connection timed out; no servers could be reached
root@knapsacker:/home/koodoo#

Then I went to http://www.dnsstuff.com/tools/aboutyou.ch

That site told me that my D.N.S. servers were :
202.54.15.5
and
202.54.103.1

So then I added these two entries also into /etc/resolv.conf and tried the entire procedure again, but got identical results.

I would again like to mention the complete scenario here :

Code:

I am connected to a proxy server which has i.p. 10.10.11.2
We have been allotted private i.p.'s and mine is : 10.10.27.204
Other information is as follows : 
default gateway : 203.200.130.1
preferred dns server : 202.54.1.30
other dns servers : 202.54.15.5 and 202.54.103.1

What should I do ?

Help needed

Thanks in anticipation.

nixcraft · 08-29-2005, 08:08 AM

Get correct IP info from your ISP or net admin coz procedure is same and it should work out

koodoo · 08-31-2005, 02:02 PM

Hi, I'm afraid I can't do that.
My University has got a dedicated lease line from the ISP, and then they have done campus wide networking.

We've been allotted these i.p.'s by the net administrator and we cannot change these.

Isn't there any way to connect to a site via telnet in a scenario like mine?
I think that there ought to be some way (Or maybe I am doing something very stupid)

Somebody, please help me out

Thanks in anticipation.

koodoo · 09-08-2005, 04:10 PM

Hi,

Finally got it to work. I changed my i.p. to the same class as that of the default gateway. (I chose 203.200.130.79 as the i.p.). Then added the default gateway 203.200.130.1 and it worked.

But the problem still remains

I just changed my i.p. to test whether telnet was working or not. I cannot permanently keep this i.p. Ultimately I will have to use something like 10.10.27.204 and then the same problem would occur again. Isn't there any workaround, so that I can keep 10.10.27.204 as my i.p. also, and still connect to the outside world via telnet ??

Thanks in anticipation.

kingkoti · 02-11-2008, 04:09 PM

this link may help u <http://www.meadowy.org/~gotoh/projects/connect>

Tinkster · 02-11-2008, 07:59 PM

Ummm .... not that we have a hard and fast rule for this, but re-animating
a thread that was dead for over 2 years is at least considered weird. Plus
the guy had his problem resolved already?

Cheers,
Tink