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Old 02-07-2006, 11:04 AM   #1
bads
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Registered: Feb 2005
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Ping Works but No Internet II


Hi,

I'm hoping that this forum can lend a hand to my lack of skills in networking.

My diagnosis so far is that "ping" works for external sites like google.com but when I open up a browser, and I've tried several, no internet sites can be reached.

Up until now all network issues I've resolved were completely fixed once "ping external_site" was working but its not the case this time. So I'm puzzled.

I found a thread from a month ago with a very similar problem but it doesn't seem to have the same solution:
showthread.php?t=406629

The machine is
Red Hat Enterprise Linux AS release 3 (Taroon Update 1)
linux 2.4.21-9

It is one of serveral almost identical machines that are working, so I think the network settings (resolve.conf) are configured correctly.

Any help would be a lifesaver. How can ping work but browser http not work???

Thanks
Brian
 
Old 02-07-2006, 11:30 AM   #2
b0nd
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Registered: Jan 2005
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ok do one thing....run
#ifconfig ppp0

Quote:
root@darkstar:~# ifconfig ppp0
ppp0 Link encap:Point-to-Point Protocol
inet addr:x.x.x.x P-t-P:x.56.215.133 Mask:255.255.255.255
UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1492 Metric:1
RX packets:33764 errors:0 dropped:0 overruns:0 frame:0
TX packets:31925 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:3
RX bytes:24820040 (23.6 Mb) TX bytes:3889853 (3.7 Mb)
then

#route add default gw x.56.215.133 (its actually your ISP's IP)

now try opeining the websites...

Quote:
My diagnosis so far is that "ping" works for external sites like google.com
ping is to test whether a machine is up or not (unless its being filtered)
so its not only to check external sites...but you can use it to check your local machines also. e.g
#ping 192.168.0.2

regards
 
Old 02-07-2006, 11:31 AM   #3
marozsas
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There is any chance you have set up a proxy server for this machine or for the browser you are using ?
At a shell type "printenv | grep -i proxy".
At the browser look in the configuration panel, if it has a proxy enabled.

At the command line, try to access a web site using a command line tool, like wget or lynx.

"wget http://www.google.com" or "lynx http://www.google.com".
If they work, them you have internet access.
 
Old 02-07-2006, 11:44 AM   #4
bads
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Registered: Feb 2005
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Hey Thanks for the help.

Quote:
Originally Posted by ruudra
ok do one thing....run
#ifconfig ppp0
ppp0: error fetching interface information: Device not found

I don't have such a device installed. Other similar machines on our network also don't have this installed and are working fine. None the less I'll look into this Point-to-Point protocol to see if that is what is missing.



Quote:
Originally Posted by ruudra
then

#route add default gw x.56.215.133 (its actually your ISP's IP)
I think the I have the gateway configured correctly. The results of "route -n" are the same on the working machines and the not-working machine.



Thanks for getting me started on some leads. I'll let you know how it goes.
 
Old 02-07-2006, 11:50 AM   #5
bads
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Registered: Feb 2005
Posts: 21

Original Poster
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Thanks for the reply.

Quote:
Originally Posted by marozsas
There is any chance you have set up a proxy server for this machine or for the browser you are using ?
At a shell type "printenv | grep -i proxy".
At the browser look in the configuration panel, if it has a proxy enabled.
it looks like printenv doesn't have any mention of a proxy.
>printenv | grep -i proxy
>

Quote:
Originally Posted by marozsas
At the command line, try to access a web site using a command line tool, like wget or lynx.

"wget http://www.google.com" or "lynx http://www.google.com".
If they work, them you have internet access.
thanks for the new tools. Can't believe I forgot about them. I have wget on the busted machine and it seems to hang after resolving the website.

>wget www.google.com
--12:33:12-- http://www.google.com/
=> `index.html'
Resolving www.google.com... done.
Connecting to www.google.com[216.239.37.104]:80... failed: Connection timed out.Connecting to www.google.com[216.239.37.99]:80... failed: Connection timed out.
Retrying.

--12:39:31-- http://www.google.com/
(try: 2) => `index.html'
Connecting to www.google.com[216.239.37.104]:80...
*then I killed it.


Thanks for the help. I'm still not sure what needs to be done, if you have anymore suggestions, or I did something wrong.
 
Old 02-07-2006, 12:11 PM   #6
marozsas
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Try to disable the firewall ("redhat-config-securitylevel") and try again...I am running out of ideas...
 
Old 02-07-2006, 01:37 PM   #7
bads
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Registered: Feb 2005
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thanks for the help. I'm thinking it must be a problem with the hardware firewall downstairs. Sorry for the trouble. I'll let you know if I find out that is the case.
 
  


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