IT Security & Network Engineering Knowledge Base

Practical documentation and technical guides on network security, firewalls, Linux systems, monitoring, and automation.
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Windows 2008 System Files

Below lists the core Windows 2008 system files. The list “Core System Files” was derived from the “System Files” list (found here). The “System Files” list was obtained using the “file name” XML tags within %WinDir%\WinSxS\Backup\*.manifest. The %WinDir%\WinSxS\Backup is a cache storage for backing up critical system files that are needed to start Windows, as … Read more

Wget – 403 Forbidden Error

Issue When trying to download a file using wget you recieve a 403 forbidden error. root@Fileserver html# wget [website] –2010-12-20 20:40:40– [website] Resolving www.maani.us… 75.125.128.242Connecting to www.maani.us|75.125.128.242|:80… connected.HTTP request sent, awaiting response… 403 Forbidden2010-12-20 20:40:41 ERROR 403: Forbidden. Solution wget -U firefox [website]

Cisco IPS v6 Risk Ratings

The Cisco IPS Sensor generates risk ratings that are assigned to alerts which provides the administrator with an indication to the severity of the alert. There are  six values which are used in the calculation of the Risk Rating : ASR (Attack severity rating) TVR (Target Value Rating) SFR (Signature fidelity Rating) ARR (Attack relevancy rating) … Read more

IP Version 6 (IPv6)

IPv4 is the current protocol used for sending data over the internet. The main issue with IPv4 is its limited address space. With the amount of available IPv4 address rapidly shrinking IPv6 overcomes this by introducing 128 bit addresses and a much larger address space to that of IPv4. 1. Changes Introduced by IPv6 Summary … Read more

Configuring the Cisco IDS Router / Switch Modules

IDSM-2 The IDSM-2 Module is a Cisco IDS blade for the Cisco 6500 switch.Once you install the module into the switch the module uses following logical ports : Port 1 Used for TCP Resets (In Promiscuous Mode) Port 2 Command and Control Port 7 Sensing Port Port 8 Sensing Port Below details the steps required … Read more

Cisco IDS Re-imaging Procedures

There are a number of reasons or circumstances where you may need to rebuild your Cisco IDS. Rebuilding refers to the reinstallation of the application software. This will tho mean that all of your configuration changes will be wiped, apart from your management configuration when reimaging your sensor via the CLI. There are 3 ways … Read more

Digital Certificates vs Digital Signatures

Digital Signatures A Digital Signature is a method to ensure data authenticity. A digital signature is created by generating a hash (message digest) against the data and then encrypting this digest using the cryptography (public or private) key. This signature is then appended to the data. Once the recipient has received the data + signature … Read more

VSFTPD : 550 Failed to change directory

By default VSFTPD does not allow the browsing of symbolic links. When you try to browse sym links you will get a message saying,        550 Failed to change directory In order to overcome this you can use the mount command. Here are the steps : [root@server ftpuser]# pwd/home/ftpuser[root@server ftpuser]# mkdir NEW_DIR[root@server ftpuser]# mount –bind … Read more

How do I restore a CS-MARS device from its Archive ?

This article provides the steps required for restoring a CS-MARS configuration (incidents, events, configuration etc) to another CS-MARS device whilst maintaining the devices original IP settings. The following steps are based on restoring the an archive from a device which is the same model and is also running the same software version. NFS Ensure that … Read more