Every switch out of box isolate devices in to their own collision domain that means those devices can only see traffics that is sent to and from them as well as some broadcast traffics. But often times as network administrator we want to keep an eye in to the network because we want to be able to see what really is going on the network so we can pipe the output to any monitoring workstation running a tool like Wireshark to analyze the packets. In order to do that cisco allow

No, it isn’t called Unreliable Data Protocol, although many will nickname it that way so they can remember it. UDP is an option at the transport layer that doesn’t provide a connection oriented or session based reliable communication; instead we say it is unreliable and connectionless. In this article I will explore in detail UDP and its operation. The best analogy I like to differentiate UDP and TCP is to consider TCP an actual phone call where you have the initial “hello”

It won’t take you too long being in a technology world to realize there is a concept out there called the OSI Model that people keep referencing again and again and again. This mythical concept that every technology personnel use to categorize layers and functionality is a foundational reality of connectivity. Thus what I would like to do in this article is to walk you through what the OSI Model is all about conceptually, then apply it to real life. If you haven’t seen it b

If you are reading this the odds are that you are already familiar with TCP infamous "Three way handshake or SYN/ACK sequence. Unfortunately that is where TCP education ends for many networkers. Despite its age TCP is a relatively complex protocol and well worth knowing intimately. This article aims to help you become more comfortable in examining TCP sequence in great details. TCP is a protocol we use when we want reliability or connection oriented transport, We have two op

Time to Live (TTL) or hop limit, is a mechanism that limits the lifespan or life of data in networking, The designers of TCP/IP realizes that it would be possible for an IP packet to circulate endlessly on a network. For any given point to to point network R1 ends up sending the packet to R2 which thinks sending back to R1 is the right way to go will make the packet go, In simple point to point environment if the routers has an inappropriate instruction they could circulate

I came across an odd little issue recently when configuring a first hop redundancy with two Vyatta routers.In high availability mechanism such as VRRP and clustering routers, traffic can be successfully forwarded over a backup system if the primary system fails; however, the Vyatta router lacks a technology for sharing a firewall between two or more Active-Active routers. If you are using two Vyatta routers on your network, one of the routers has to be on standby mode until t

If you are like me, Who went through the pain trying to capture Vyatta's connection-tracking table for trouble shooting purposes, You will find this article very helpfull,Capturing the contrack-table will help you get information about the IP addresses that comes in and out of your Vyatta routers with all the source and destination port numbers. Because, The Vyatta routers don't save the conntrack-table by default on their logs, You will have to capture it manually by editi

DoD and DDoS Attack A denial of service (DoS) attack is a malicious attempt to make a server or a network resource unavailable to users, usually by temporarily interrupting or sending the services of a host connected to the internet. Although a DoS attack does not usually result in the theft of information or security loss, it can cost the targeted person or company a great deal of time and money. Typically, the loss of the service is the inability of a particular network s

One of my favorite packet switching technology is MPLS. Mpls allows most packet to be forwarded at Layer-2 (the switching level) rather than having to be passed up to Layer-3 (the routing level). Each packet gets labeled on entry into the service provider's network by the ingress router. MPLS gives network oprators a great deal of flexibility to divert and route traffic around link failure, congestion, and bottleneck.This article might help you out when configuring MPLS betwe

Why do we need SSL Certification in the first place Well there is HTTPS Server on the WLC enabled by default for web administration & Web Policy (Web Authentication/Pass through). Provide SSL Encryption between Wireless Clients & WLC to protect web authentication.The issue begins when an end user receives a security warning When Triggering the web policy page on the WLC. A Self-Signed Certificate (SSC) is installed on the WLC by default.The solution is to Deploy a 3rd Party

Cyber security involves protecting information and system from major threats such as Cyber warfare, Cyber espionage and cyber terrorism.Cyber threats takes aim at governments, military, corporations, financial institutions, hospitals and other businesses that collect, process and store a great deal of confidential information on computers and transmit that data across networks to other computers. With the growing volume and sophistication of cyber attacks, ongoing attention