14 Dec 2017

IPv6 to IPv4 Tunnel: How to set up an IPv6 tunnel between two Cisco routers to route IPv6 packets through IPv4 network.


With the world, fast running out of IPv4 and countries like China far gone in IPv6 implementation, the probability of your organisation acquiring or going into a merger with another organisation whose network is built on IPv6 is quite high. As a network engineer, it is your responsibility when such happens, to find a way to route the newly acquired organisation's IPv6 traffics through the very popular IPv4 internet. In this demonstration, I will share with us on how to configure your Cisco routers to accept IPv6 traffics and route them through IPv4 networks. 

13 Dec 2017

Stop wasting money on technicians: See how to unlock phones to use any network.

We all know that locked phones are quite cheaper than factory unlocked phones. Companies like Verizon, Sprint, AT&T, and T-Mobile often use this as a sales technique to get subscribers on their networks. To the users, everything is fine as long as they remain on the networks the phones are locked to. The problem starts when there is an attempt to use the device on a network on which the device is not locked. Most phone technicians often charge huge amount of money to have these device unlocked. Having studied the situation and observed how simple it is to unlock this devices, I have decided to make this post as a guide on how you can do it yourself at less than one third of the amount paid to technicians.

Port forwarding: how to configure static NAT to allow access to internal web server using the public IP on your router.


From the network topology, we have a web server that has been assigned a private IP address for security reasons. The task is to configure router A to statically allow access to the web server on port 80 for all in-coming traffics to the public IP assigned to the router. In this demonstration, out ISP assigned public IP is 192.168.2.1 while the web server's privately assigned IP is 192.168.1.3.

12 Dec 2017

Network Address Translation (NAT) configuration on a Cisco router, from start to finish.


NAT is a feature that allows internet access for users who are connected using private addresses. Because IP version 4 only provides about 4.2 billion addresses, which is below the required number of IP addresses for devices that need to be connected to the internet, NAT was introduced to allow a group of users who have been assigned IP addresses from the private address blocks, to share one or more public IP addresses for traffics that are internet-bound. In this article, we will look as the good and bad side of NAT as well as its configuration on a Cisco router.

How to determine the source IP address of an email and use it to trace the sender's location.


With email scams on the increase even as email service providers are constantly re-engineering their anti-spam algorithm to identify and fish out email spams, cooperate organisations and individuals are losing huge amounts of money to these cyber criminals who leverage on the power of the internet to dish out irreparable damages to unsuspecting users. In this post, I want to share with us on how to identify the source IP address on an email and with the help of another internet facility, determine the location of the sender of such email. For someone who has been scammed, this is probably the first step of the investigation to uncover the face behind the scam.

11 Dec 2017

Wireless connectivity: how to choose the best equipment for long distance wireless links


Wireless is the new darling of the industry and understandably so, everyone is jumping at it. For a successful deployment of a wireless link using the unlicensed 5GHz frequency spectrum, you need to understand the equipment that meet your requirements. Apart from line of sight, factors like distance, bandwidth requirement, and interference must be put into consideration when planning for the deployment of wireless links. In this article, I will be sharing with us how to choose the best equipment given some requirements from a client.

Cisco CCNA: Implementing EIGRP with VLSM and manual summarization. See all eigrp show commands and their functions.


The enhanced interior gateway routing protocol is no doubt one of the best routing protocols that you can configure on your network. Apart from its support for VLSM, eigrp supports route authentication and manual summarization, making it one of the fastest internal routing protocols out there. In this demonstration, I will share with us how to implement eigrp to support VLSM and how to use the various eigrp show commands to troubleshoot eigrp routing issues. LAB: Configure eigrp for the networks in the topology below.

8 Dec 2017

Cisco CCNA: Powering on Cisco routers. Boot process explained, from start to finish.


It is very easy for one to know how to use a Cisco router without knowing the various stages involved during its boot process. As a network engineer, it is required of you to understand these stages, not just for certification exam purposes but to help in your career as a network engineer. In this post, I will share with us the various stages of the router's boot process and the events that happen at each stage.