[afnog] connection to www.cnn.com

Mon Jun 5 17:35:07 EAT 2006

On Mon, Jun 05, 2006 at 12:37:55PM +0300, Mikisa Richard wrote:
> I can telnet to www.cnn.com 80 successfully but I can not bring down the 
> page.
> 
>  mayhem:~ # telnet www.cnn.com 80
> Trying 64.236.16.84...
> Connected to www.cnn.com.
> Escape character is '^]'.
> 
> a subsequent  GET / HTTP/1.0 yield nothing.

That is an incomplete command. The server will not respond until you issue a
complete HTTP request. A valid example is:

GET / HTTP/1.0
Host: www.cnn.com
<blank line>

The final <blank line> - just press Enter again - is what terminates the
HTTP request, and at that point the server should respond.

If you get no response at this point, then try the following test, sending a
malformed HTTP command - just type "asdfasdf" and Enter.

$ telnet www.cnn.com 80
Trying 64.236.29.120...
Connected to www.cnn.com.
Escape character is '^]'.
asdfasdf
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>501 Method Not Implemented</title>
</head><body>
<h1>Method Not Implemented</h1>
<p>asdfasdf to / not supported.<br />
</p>
<hr>
<address>Apache Server at www.cnn.com Port 80</address>
</body></html>
Connection closed by foreign host.

If you can see that, then most likely the problem is an MTU issue as
described elsewhere in this thread. That is, CNN can send small packets to
you, but 1500-byte packets are being dropped instead of fragmented. If this
is the case we can talk you through the problem some more.

IP can cope with smaller MTUs, but you can get bitten by this problem if you
block ICMP. At the moment, if I try to ping 41.220.0.4 I get no response,
although I can ping 41.220.0.1. It could just mean that host .4 is down.

Regards,

Brian.