ipv4magicnumbersmallOne of the most crucial skill in networking is calculating network address and  usable network space based on given IP address and prefix only. These actions are also known as reverse engineering and if you won’t get to know this “networking nursery” don’t dream about dealing with computer networks seriously. Applying binary system is cumbersome and very time consuming (especially if you are rookie) so maybe someone ingenious has invented something better ? 

opticalfibresmall12Optical fiber as a medium got many virtues. Unlike copper media (e.g cat6e), WiFi (e.g 2,4 GHz, 5 GHz or Bluetooth) optical fiber is not exposed to EMI (electromagnetic pulse), interferences, signal interceptions. Usually is not limited by weather conditions, lay of the land (wifi), short length of a segment (cat5e). But even so sophisticated medium as optical fiber has got downsides caused by  laws of physics. 

vtitunnelsmall1VTI – Virtual Tunnel Interface has been invented as a simple deployment of VPN in conjunction with IPSec. Easiness of implementation, multicasts and QoS support, makes VTI interesting alternative to GRE Tunnel.

Analog-Digital-Electronic-Components“Nothing dies in nature”. This proverb reflects very well two the most important laws in electrotechnics : Current and Voltage Kirchhoff’s laws which are fundamental in study of electrotechnics. Regardless you are designer or electronic technician, well understanding how  current behaves in closed circuit is prerequisite if you are going to fix or design electronic appliances. 

mplsCisco Express Forwarding (CEF) the technology which has been invented by Cisco   omitted layer 3 in order to accelerate packets switching. It has increased significantly the efficiency and speed of packets forwarding, but there was a problem because CEF is Cisco proprietary and has worked only with Cisco devices. Then  MPLS has been invented as an expansion of CEF and as an open standard solution.

ospf-default-route smallIn both routing protocols OSPF and EIGRP route summarization and default route propagation are crucial, especially if you have complex network with a lot of prefixes. Properly implemented summarization can save a lot of router resources. Let’s check how to implement both features and what is “mystery” null0 interface involved in summarization.

business-Firewall1The traffic control systems, besides a security function realize the following functions: traffic filtering, bandwidth limitation, collecting information about traffic characteristic. Each of mentioned device in the title, perform similar task but work in different way. Deployment one of them depends on network size, efficiency, utilized solutions (i.e remote access). They may work on different OSI layers and deal better or worse with different threats.

osi-model1Both OSI model and TCP/IP stack (they roles partly overlap themselves)  describe standards and framework of network communication. If they didn’t exist communication between network appliances of different vendors wouldn’t be possible. On the other words, 7 Layers of OSI model enable protocols being visible to each other. But what exactly those protocols and layers are? What exactly happens with information during receiving and how it  runs on particular network layers ? How information is being changed from electric impulse to the usable form ? 

eigrp-variance-exa2mple-topologyEnhanced Interior Gateway Routing Protocol (EIGRP) is considered deprecated routing protocol. In my opinion unfairly. Despite  EIGRP is distance vector protocol (or rather hybrid protocol) is still being utilized in small and medium networks. Reliability and efficiency in connection with simplicity of deployment  make EIGRP still worth of considering routing protocol, especially, that has DUAL algorithm .

itil-service-strategyITIL has been invented to facilitate management of IT services. Regardless what department or environment you work for, whether it is small helpdesk, game designing company or even hospital, because ITIL is versatile and universal. Successfully deployed ITIL rules and best practices will organize and improve work and efficiency in your company.