My name is Harris Andrea and I would like to extend a warm welcome to you. About me in a few words. Let me tell you a story. When I was in my last year in University (in the late 90’s) I had to take some courses around TCP/IP and computer networking. That was the […]
Network Failover Redundancy Scenario – Two sites with two ASA Firewalls
A few months ago I was involved in a project where we had to design a network redundancy scenario with two physically separate networks in two different buildings (the sites were a few kilometers away from each other). The main requirement was to provide Inbound Internet Access to two Server Pools (Linux Servers in High […]
Make Your Home Future Proof With A Home Network
In the past computer networking was the reserve of office places and businesses utilizing computer systems and shared software for completing demanding workload tasks. However, since the introduction of the PC to the home, primarily in the form of the desktop computer, the need for home networking has become an almost everyday necessity. No Longer […]
Troubleshooting Skills and Training are Essential in Networking
One of the most important skills that a network engineer must learn and develop is troubleshooting. I have designed, configured and managed hundreds of networking projects. Its very rare to configure a network (especially complex ones) and have everything running as expected from the first shot. Most of the times a lot of troubleshooting activity […]
Characteristics of dynamic IP routing protocols
Below are some important characteristics of various Dynamic Routing Protocols that are used in Cisco IOS routers. RIPv2 * Distance Vector Protocol. * Suitable for small to medium networks. * Average convergence speed. * Supports VLSM. * Supports CIDR. * Standardized protocols (supports multi-vendor networks.) * Multicast address for updates: 224.0.0.9 * Administrative distance: 120. […]
Important Points to Know About IPV6
We are slowly approaching the implementation of IPv6 in a mass scale and thus we must be ready to learn some significant differences over IPv4. Also, some IP addressing terms will start to appear with increasing frequency in our day to day work. So let’s see some notable concepts that you need to know about […]
GNS3 Graphical Network Simulator
GNS3 is a graphical network simulator that allows simulation of complex networks. To allow complete simulations, GNS3 is strongly linked with : * Dynamips, the core program that allows Cisco IOS emulation. * Dynagen, a text-based front-end for Dynamips. * Qemu, a generic and open source machine emulator and virtualizer. GNS3 is an excellent complementary […]
IEEE 802.3ba Standard -100 Gbps Ethernet is Here
On June 17th, the IEEE has ratified the 802.3ba standard for Ethernet connections with speeds of 40 and 100 Gbps. Both Cisco and Juniper have been supplying high performance network equipment which support the above standard. Cisco for example supports the 100Gbps Ethernet card on its CRS-3 router, while Juniper supports its 100Gbps PIC card […]
IPv4 addresses are running out
It is beyond discussion that the full implementation of IPv6 in all Internet services and infrastructures will take place sooner or later. However, a harsh reality has knocked our door a few months ago. The Number Resource Organization (NRO) has warned that the available free IPV4 address space has fallen below 10%, which is considered […]
Routing Protocols Overview
There are different techniques and methods for maintaining accurate routing information, thus different types of routing protocols were invented over the years. The following post is intended to offer you an overview of the different types of routing protocols currently available. Distance Vector / Link State The above terms refer to the algorithms that govern […]
Most Popular Blog Posts for 2009
As the end of the year is almost here, I have decided to make a round-up of my blog posting activity for year 2009. I have gathered the 3 most popular posts for my blog in 2009 and listed them below. It seems that anything related with Cisco ASA Firewalls is very popular. This is […]
Cisco Branch Virtual Office Solutions – Network Design
Extending the central office enterprise environment to remote branch office locations gives employees greater flexibility while enhancing productivity and reducing costs. Cisco Virtual Office solution is an umbrella of technologies and products that delivers secure data, voice, and video communication to remote teleworkers and branch offices, providing to remote employees a seamless office-caliber experience to […]
Passing non-IP Traffic over IPSEC VPN using GRE over IPSEC
IPSEC VPN is a great technology for encrypting and securing communications between networks (used also in VPN software clients as well). The only drawback is that IPSEC supports ONLY pure IP unicast traffic and nothing else. If you want to securely pass multicast or non-IP traffic between sites then IPSEC alone will not work. Fortunately Cisco […]