What are the differences in closed, open, and filtered ports on a firewall? | Using nmap or other tools, you may have seen results that say open, closed, or filtered. Here is some insight into what this all means!
Google Authenticator Two-Factor SSH Authentication for Debian Wheezy | Debian does not provide a package for Wheezy to use Google Authenticator as a pam module. However, you can grab and install the Jessie (Debian testing) deb. Here are some steps!
Configure nginx for PFS and ssllabs.com A Rating | Here is a quick configuration for nginx to achieve an ‘A’ score on ssllabs.com. This example is from Debian Wheezy using OpenSSL 1.0.1e and nginx 1.2.1 and also enables Perfect Forward Secrecy as added security against the NSA or other snooping!
Postfix – Relay local mail to External Email Address | For good practice, one should receive root mail from your Linux server. Linux typically sends all sorts of important cron messages, alerts, logwatch emails, and other info to root@localhost. I’ll show you how to use Postfix to relay this local mail to your own external email account such as a gmail account!