Debian Admin

Debian/Ubuntu Linux System Administration Tutorials,Howtos,Tips

  • RSS Subscribe

    subscribe to the Debian Admin RSS feed
  • Sponsors



  • Categories

  • Sponsors

  • Support DebianAdmin

    Amount $:
    Website(Optional):


  • Meta

  • Archives



Archive for the 'Security' Category


How to filter spam with Spamassassin and Postfix in Debian

Posted by Admin on 1st April 2008

If you're new here, you may want to subscribe to my RSS feed. Thanks for visiting!

We have already discussed how to install mail server with postfix+Devcot+SASL+Squirrel Mail in this article we will see how to add spam filter for postfix mail server.

Apache SpamAssassin is an extensible email filter that is used to identify spam. Once identified, the mail can then be optionally tagged as spam for later filtering. It provides a command line tool to perform filtering, a client-server system to filter large volumes of mail, and Mail::SpamAssassin, a set of Perl modules allowing Apache SpamAssassin to be used in a wide variety of email systems.

Read the rest of this entry »

Share/Save/Bookmark

Posted in General, Security | 16 Comments »

autossh - Automatically restart SSH sessions and tunnels

Posted by Admin on 17th March 2008

autossh is a program to start an instance of ssh and monitor it, restarting it as necessary should it die or stop passing traffic. The idea is from rstunnel (Reliable SSH Tunnel), but implemented in C. Connection monitoring is done using a loop of port forwardings. It backs off on the rate of connection attempts when experiencing rapid failures such as connection refused.

Read the rest of this entry »

Share/Save/Bookmark

Posted in Free-Tools, Security | No Comments »

Access Network When Everything Else is Blocked Using ptunnel

Posted by Admin on 16th January 2008

Ptunnel is an application that allows you to reliably tunnel TCP connections to a remote host using ICMP echo request and reply packets, commonly known as ping requests and replies. At first glance, this might seem like a rather useless thing to do, but it can actually come in handy in some cases. The following example illustrates the main motivation in creating ptunnel:

Read the rest of this entry »

Share/Save/Bookmark

Posted in Network, Security | No Comments »

Lynis - Security and system auditing tool

Posted by Admin on 24th December 2007

Lynis is an auditing tool which tests and gathers information from Unix based systems. The audience for this tool are security and system auditors, network specialists and system maintainers.

Read the rest of this entry »

Share/Save/Bookmark

Posted in Security | No Comments »

ssh on multiple servers Using cluster ssh

Posted by Admin on 29th November 2007

Cluster SSH opens terminal windows with connections to specified hosts and an administration console. Any text typed into the administration console is replicated to all other connected and active windows. This tool is intended for, but not limited to, cluster administration where the same configuration or commands must be run on each node within the cluster. Performing these commands all at once via this tool ensures all nodes are kept in sync.

Read the rest of this entry »

Share/Save/Bookmark

Posted in General, Security | No Comments »

Securing Cisco Routers by Disabling Unused Services

Posted by Admin on 12th November 2007

On Cisco routers, a whole bunch of services come enabled by default.your first order of operation would be to ensure that the all unused services are disabled.

Now we will see how to disable some services on cisco router for security purpose.

Read the rest of this entry »

Share/Save/Bookmark

Posted in Security | No Comments »