Cisco Packet Tracer is a network simulation tool used to help students prepare for
Cisco networking exams. Unlike its competitor GNS3,
Cisco Packet Tracer only supports a subset of possible commands and scenarios. GNS3
is used in a professional environment to model the network before implementing it or making changes.
Cisco Packet Tracer is a student aid for a very specific purpose (Cisco exams).
This means we can't do some things realistically on Cisco Packet Tracer but we can do these on
GNS3. For example, you can set up full featured web servers, ftp servers, etc. with multiple operating systems on GNS3, but Cisco Packet Tracer provides very simplified versions of these. However, Cisco Packet Tracer is easy to set up and use and doesn't require too much computing resources. In GNS3, every device on the simulation is a virtual machine- you literally have to set up every server to get them to work. That GNS3 requires every device to be a virtual machine means it sucks up huge computing resources.
This section of the website provides exercises in Cisco Packet Tracer to teach various networking
concepts.
This exercise teaches students how to set up a router to
connect two different networks together.
Two Router Lab
This exercise introduces students to the ideas that routers
can be physically modified and the routing table.
Internal Routing Lab
This exercise introduces students to configuring
EIGRP and OSPF on a network and how to get EIGRP and OSPF to talk to each other.
DHCP Lab
This exercise introduces students to configuring
DHCP on a router so there is no need to manually allocate IP addresses to DTEs.
WiFi Configuration
This exercise introduces students to configuring
the home router, modeling the home router as its component logical parts (router, switch, wireless access point), the idea of managing frequencies across wireless access points, and configuring a wireless LAN controller with associated Lightweight Access Points.
VLAN Configuration
This exercise introduces students to configuring
virtual LANs. The idea behind a virtual LAN is to disassociate the machine's IP
address from a physical interface. Until VLANs, one router interface could only be used
for one subnet.
Here, we show that one router interface can be used for several subnets. We also
introduce the layer 3 switch which can be used to create virtual interfaces.
These virtual interfaces, in turn, allow us to (for example) have IP addresses
from the same subnet across different layer 2 switches.
DNS and Server Configuration
This exercise introduces students to configuring
Domain Name Service on their networks. Domain Name Service attaches a human-readable label
to an IP address. In addition, we add a web, FTP, and email service to our network.
I explain to my class that how Packet Tracer models service configuration is
simplistic. How DNS is configured is reasonably close to what actually happens.
However, Packet Tracer doesn't model the actual installation of DNS service software.
Furthermore, configuring web, ftp and mail service can be a nightmare.
I have separate videos where I show how DNS is configured and what web and FTP
server configurations look like.
Border Gateway Protocol
This exercise introduces students to Border Gateway Protocol,
the protocol that is used to communicate across the Internet. Students learn about
AS numbers as important numbers signifying organizations. Students also learn how
to get BGP to talk to EIGRP and OSPF.
Network Address Translation
This exercise teaches students how to configure
Network Address Translation (NAT). NAT is used to map an internal IP address
to an external IP address. Students are shown how to set up static NAT for
services and dynamic NAT for clients seeking to connect to services on the Internet.
The lab also explores the idea of internal versus external domain names and
domain name forwarding. It is shown that if one uses internal domain names,
one needs both an internal DNS and an external DNS to show external parties
the public IP address of the internal server.