Linux Web Troubleshooting
From ben.goodacre.name/tech
Contents |
Telnet port 80
Allows all output to be seen for easier troubleshooting.
[user@host ~]$ telnet google.com 80 Trying 209.85.229.99... Connected to google.com. Escape character is '^]'. GET / HTTP/1.0 302 Found Location: http://www.google.co.uk/ Cache-Control: private Content-Type: text/html; charset=UTF-8 Set-Cookie: PREF=ID=aca7ce20b11489b5:TM=1273490037:LM=1273490037:S=efOcyW5HLidr1H2B; expires=Wed, 09-May-2012 11:13:57 GMT; path=/; domain=.google.com Date: Mon, 10 May 2010 11:13:57 GMT Server: gws Content-Length: 221 X-XSS-Protection: 1; mode=block <HTML><HEAD><meta http-equiv="content-type" content="text/html;charset=utf-8"> <TITLE>302 Moved</TITLE></HEAD><BODY> <H1>302 Moved</H1> The document has moved <A HREF="http://www.google.co.uk/">here</A>. </BODY></HTML> Connection closed by foreign host.
See Also
OpenSSL s_client for telnet-like troubleshooting for SSL connections
Ensure that openssl is installed.
openssl s_client -connect hostname:port
Normal GET and HEAD etc. statements can now be typed in as if it was a normal HTTP session.
View packets in tcpdump
If networking needs to be eliminated from troubleshooting.
Run this on a client:
sudo tcpdump -s 0 -X 'tcp dst port 80'
And/or the following on a server:
sudo tcpdump -s 0 -X 'tcp host client.ip.address'
This will show the full ASCII packet. Obviously this will not work for SSL connections.
