This is one of the GNS3 topologies which we’ll configure as part of this course.
This GNS3 topology is utilizing the GNS3 VM
and I’ve loaded IOSvL2 images to the GNS3 VM
In addition I am using a Cisco IOS router image
also running within the GNS3 VM
and I have that image available on both the local GNS3 server
in other words running within Windows as well as on the GNS3 VM
Under edit I am going to preferences and I’ve configured an image
running on the local serveras well as the GNS3 VM
You don’t have to configure the image in both places
I’ve just done that for a various demonstrations in the Course
I’ve also got an NPM server which I’ll use to manage this network using SNMP
I’ll configure the various parts of this network throughout the course
but at the end of the course
I’ll have all of these videos together in one place
so if you want to watch all of the config in a one go you can do that
Now don’t worry too much if you don’t know all the terms
that I am going to be using in this explanation
We’ll be discussing this throughout the course
but this topology gives us a nice scenario
to build upon and shows you how the different technologies
that we’re learning about can be implemented in a proper network
In this topology we have 2 core switches
as well as 2 access switches
but pretend that we have more than 2 access switches
Configuring more than 2 is kind of redundant
in what we're doing here but I'll perhaps
extend this topology and make it more complex
to show you a larger topology as part of this scenario
Various things need to be configured in this network
we have to configure IP Addressing
we have to confugure VLANs
we have to configure VTP or VLAN Trunking Protocol
We've got to configure Inter-VLAN routing
between the various IP Addresses
We've got to configure links such as these as trunk ports
these links Gigabit02 on the Access Switch
needs to be configured as Access Ports
the reason why is that
this router, router1 is going to be configured in VLAN10
and is going to act as a host in the network
so we're actually using a Cisco IOS image
but it's going to mimic a host device
tha same with this router which is going to be
configured in VLAN20
So this will also act as a PC in our topology
Router2 is acting like PC2 in our topology
but ratehr than using PCs to do this
I want to show you how to configure routers
with static routes and various other options
to enable connectivity in the network
Router3 is going to act as our gateway to the outside world
so this router will be configured with NAT or Network Address Translation
and an actual fact it will be using Port Address Translation or PAT
to NAT these routers acting as PCs
unto the Internet so that they can access
sites such as Google.com and others
This topology is gonna run as a Layer2 topology
so we need to configure Spanning Tree
Spanning Tree is enabled by default on Cisco Switches
In this example we want to optimize
Spanning Tree so we will configure PVST
with this switch as the root for VLAN1 and VLAN10
and this switch has the root for VLAN20
so Router2 acting as PC2 is gonna send traffic to the core
using this uplink whereas Router1
acting as PC1 is gonna sent traffic to the core using this uplink
We also have to think about the default gateways
If Router1 acting as PC1 has Switch1 as its default gateway
Switch1 will only be able to do
Inter-VLAN Routing for Router1 or PC1 when it's up
However if Switch1 goes down this PC
will no longer be able to ping PC2
or be able to access the Internet
So we're going to want to implement
HSRP or Hot Standby Routing Protocol
to ensure that the default gateways of the PCs
is in our topology are still available
when one of the switches go down
so we will configure HSRP for our user PCsin this topology
sio that they can continue working
even when one of the core switches goes down
This toplogy have redundancy in it
but Spanning Tree will block ports
to stop loops in the topology
and may stop ports that you least expects
So we need to optimize Spanning Tree
but not only making Switch1 the root for some VLANs
and Switch2 the root for other VLANs
But we also want to enable Link Aggregation or EtherChannel
on these 2 core links
Spanning Tree is gonna block one of this ports
which negates the purpose of having
multiple ports in the core between our core switches
so we're gonna want to bond these 2 links together in the Link Aggregation
Once we've configured the network
we'll test connectivity between PC1 and PC2
and will test failover to ensure
that our network provides redundancy
when one of the switches in the core goes down
we'll also as mentioned test connectivity to the Internet
and thus we will need to enable a NAT on Router3
we will also need to enable Routing Protocols on our routers
and inject a default route from Router3
So we'll need to enable OSPF or EIGRP
on our core devices and then advertise
the default Internet route from Router3
to both core switches
We'll also need to enable Simple Network Management Protocol or SNMP
on our switches so that Network Performance Monitor
can manage the network
In addition we're gonna want to use a syslog server
to sent or restore our log information
so we'll use NPM to receive syslog messages
from our devices
I'll include link to load a video
where you can load a free trial version
of Network Performance Monitor
So there's a lot to do to get this topology to work
I'll explain the configuration as I am going through this
but for the basic theory please refer to the
relevant modules in the course
So lots to do. Let's get started configuring this topology