The Three Tiers

Working towards the CCNA Cisco talks about a hierarchical network there are three layers to this design. Access Layer, distribution layer and the core layer. Each of them have their own set of functions and is also considered to be a best practice when the network continues to grow and for redundancy along with just a better way to manage it. Continue reading “The Three Tiers”

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The Codes of ICMP

In today’s post I wanted to talk about the widely used Ping command. Which is one of the best methods (I think) to begin network troubleshooting. When part of the network goes down it is sometimes hard to figure out why? When you issue the ping command or the extended ping command in a Cisco router several ICMP codes can come up on the router. Let’s discuss them! Continue reading “The Codes of ICMP”

The Beginnings of Layer Two Redundancy

In a perfect world we would never need redundancy on a network infrastructure, but as you know as well as I know we don’t live in a perfect world. Hardware will eventually fail, bottlenecks will appear, and the speed of our network will become slower when we max the bandwidth on links. So having redundancy in routers, connections, and having a hierarchy network is one of best choices to make when improving the efficiently of the network. But in the OSI model there is one layer that can’t have redundancy at least logically and that is Layer two of the OSI model. Continue reading “The Beginnings of Layer Two Redundancy”

Cisco Discovery Protocol

In today’s post let’s talk about CDP the Cisco Discovery Protocol. This protocol helps us in two ways, it first helps us verify that a connection between router or switch is set up correctly  at least up to layer two in the OSI model. This also helps us discover Cisco devices that are in are network and which interfaces these devices are connected too and from are Cisco equipment. The Cisco discovery protocol is Cisco proprietary  and before I go any further let me mention that CDP is a security risk because of the detailed information CDP gives out which helps you has a network administrator build a current network infrastructure, this can also hurt you because this information can easily be sniffed by programs that are easily searched on the internet. Continue reading “Cisco Discovery Protocol”

Distance Vector Routing

Couple weeks ago I talked about routing protocols and in the post I mentioned two routing protocol features distance vector and link state. Although these protocols fundamentally do the same thing by getting information on remote networks they get this information in a different way. For today let’s introduce distance vector routing. Continue reading “Distance Vector Routing”