Command Line SSL Connections

As part of troubleshooting a system, testing network connectivity and working communication channels is pretty important.

For example, to test an HTTP server, use these commands:

telnet www.google.com 80
GET / HTTP/1.0


with 2 enters after the GET line. Then you will get to see exactly how the server responds.

Sometimes it would be nice to test an SSL connection, to see what the server is saying. Thanks to Tony Copping for showing me this.

openssl s_client -showcerts -connect www.google.com:443

Command Line LDAP Access

ldapsearch -x -h 192.168.0.1 -b "o=CoName,c=US"
ldapsearch -x -h 192.168.0.1 -b "o=CoName,c=US" "cn=Jaye WhatsHisName"

Linux Hard Limits for Open Files

Found in:

/etc/security/limits.conf

Sticky Directories

When the sticky bit is set on a directory, firles i that directory may be unlinked or renamed only by root or their owner. Without the sticky bit, anyone able to write to the directory can delete or rename files. The sticky bit is commonly found on directories such as /tmp, that are world-writable.