IT Security & Network Engineering Knowledge Base

Practical documentation and technical guides on network security, firewalls, Linux systems, monitoring, and automation.
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How do i include the cluster state within the ASA hostname ?

The prompt state command was introduced within 7.1. This short example shows you how to configure your ASA to include the cluster state within its name : cisco-firewall# config t cisco-firewall (config)# prompt hostname state  cisco-firewall/act(config)#

How to determine the Syslog Facility using Tcpdump

Each Syslog message contains a priority value. The priority value is enclosed within the characters < >. The priority value can be between 0 and 191 and consists of a Facility value and a Level value. Facility being the type of message, such as a kernel or mail message. And level being a severity level … Read more

Oracle 11g Fedora 13 Error in invoking target ‘agent nmb nmo nmhs tclexec’

When installing Oracle 11g on Fedora 13 you may get the following error :               Error in invoking target ‘agent nmb nmo nmhs tclexec’ of makefile ‘/u01/app/oracle/product/11.1.0/db_1/sysman/lib/ins_emagent.mk Solution Within the file detailed in the error edit it and find the line that reads ‘$(MK_EMAGENT_NMECTL)’ change this to ‘$(MK_EMAGENT_NMECTL) -lnnz11’ Note : edit this file while … Read more

Installing GNS3 0.7.2 onto Fedora 13

Below shows you how to install GNS3 onto Fedora 13. GNS is a Graphical Network Simulator allowing you to build virtual Cisco networks. yum -y install PyQt4 wget telnet qemu xtermcd ~wget http://downloads.sourceforge.net/gns-3/GNS3-0.7.2-src.zip?downloadunzip GNS3-0.7.2-src.zip && rm -f GNS3-0.7.2-src.zipmv GNS3-0.7.2-src /opt/GNS3cd /opt/GNS3mkdir Dynamipsmkdir IOSmkdir Projectmkdir Cachemkdir tmpchmod o+rw -R ./Projectchmod o+rw -R ./tmpcd Dynamipswget chmod +x … Read more

Configure Pre-Shared Site to Site VPN between Cisco Routers

Below shows the configuration for one side of a Site to Site VPN between 2 Cisco routers using pre-shared keys. router(config)# crypto isakmp enable Phase 1 router(config)# crypto isakmp policy 10 router(config-isakmp)# authenticaton pre-share router(config-isakmp)# encryption [?] router(config-isakmp)# group [?] router(config-isakmp)# hash [?] router(config-isakmp)# lifetime 86400 router(config)# crypto isakmp identity address router(config)# cryption isakmp [key] … Read more

IPv4 Subnetting Notes

The other day someone asked me to explain subnetting. It had been a while so I dusted off my CCNA books and attempted to answer his questions. So I thought this would be an ideal time to jot down some notes for future reference. This isnt a tutorial or guide but just some some notes … Read more

Types of IDS Alerts

There are 4 main types of IDS alerts. These are :  True Positive Bad traffic which triggers an alert.  False Positive Good traffic which triggers an alert. False Negative Bad traffic, but no alert is raised. True Negative Good traffic, and no alert is raised.

How to run vSphere using SSH tunnelling

This guide looks at running your vSphere Client through SSH tunnels. You may need to do this due to having a Proxy in place or your firewall is blocking the required ports you need in order to run vSphere. 1. First of all edit your hosts file to include an entry for you ESX box. … Read more

Compiling Rancid on an x86 Solaris 10 platform

Below shows you the steps in order to compile Rancid on an x86 Solaris 10 platform. RANCID monitors a router’s (or more generally a device’s) configuration, including software and hardware (cards, serial numbers, etc) and uses CVS or Subversion to maintain history of changes. Space on /var If you havent much space on /var run … Read more