Category Archives: Security – CCNA / CCNP Security

ASA Failover and Redundancy

The following must be identical: Model (5505 or 5510 or 5520, etc) Amount of RAM Number of Interfaces (should be the same type as well) External Modules (CSC-SSM or IPS-SSM) Activation key with the same features Failover mode Encryption Level Number of VPN peers *** Same size Flash is not required **** Definitions: Active -> ResponsibelContinue reading “ASA Failover and Redundancy”

Cisco ASA Firewall Active / Standby Failover

The Cisco ASA firewall is often an important device in the network. We use it for (remote access) VPNs, NAT/PAT, filtering and more. Since it’s such an important device it’s a good idea to have a second ASA in case the first one fails. The ASA supports active/standby failover which means one ASA becomes theContinue reading “Cisco ASA Firewall Active / Standby Failover”

Martian Packet Messages

Occasionally, you might see messages like the following in your Linux kernel messages: martian source 192.168.1.1 from 127.0.0.1, on dev eth1<br />         ll header: 52:54:00:98:99:d0:52:54:00:de:d8:10:08:00 There’s a lot of discussion out there about what this means, but not a lot about how to trace down the source.  Hopefully this will provideContinue reading “Martian Packet Messages”

Deep Packet inspection (DPI) / Layer 7 application recognition / Network Based application recognition (NBAR)

Deep packet inspection (DPI) is an advanced method of packet filtering that functions at the Application layer of the OSI (Open Systems Interconnection) reference model. The use of DPI makes it possible to find, identify, classify, reroute or block packets with specific data or code payloads that conventional packet filtering, which examines only packet headers,Continue reading “Deep Packet inspection (DPI) / Layer 7 application recognition / Network Based application recognition (NBAR)”

How to use OpenPuff steganography to send sensitive info securely

How to use OpenPuff steganography to send sensitive info securely Video link: http://searchsecurity.techtarget.com/video/How-to-use-OpenPuff-steganography-to-send-sensitive-info-securely Former National Security Agency (NSA) contractor Edward Snowden’s revelations regarding the spying activities of the U.S. government and others dealta devastating blow to some of the bedrocks of information security, including the trustworthiness of encryption and virtual private networks (VPN). Now, organizations worldwideContinue reading “How to use OpenPuff steganography to send sensitive info securely”

Shellshock (bash vulnerability/bash bug)(Deadly serious’ new vulnerability found)(All OS X and Linux systems wide open)

A new vulnerability has been found that potentially affects most versions of the Linux and Unix operating systems, in addition to Mac OS X (which is based around Unix). Known as the “Bash Bug” or “ShellShock,” the GNU Bash Remote Code Execution Vulnerability (CVE-2014-6271) could allow an attacker to gain control over a targeted computerContinue reading “Shellshock (bash vulnerability/bash bug)(Deadly serious’ new vulnerability found)(All OS X and Linux systems wide open)”

Understanding the Eight Basic Commands on a Cisco ASA Security Appliance

There are literally thousands of commands and sub-commands available to configure a Cisco security appliance.  As you gain knowledge of the appliance, you will use more and more of the commands.  Initially, however, there are just a few commands required to configure basic functionality on the appliance.  Basic functionality is defined as allowing inside hostsContinue reading “Understanding the Eight Basic Commands on a Cisco ASA Security Appliance”