CPT Simulacijski način rada eng v3

Summary

This video provides an introduction to the Packet Tracer simulation environment, explaining the differences between real-time and simulation modes. It covers how to control and observe network traffic, manage time progression, and interact with tools like the simulation panel, packet filters, and complex PDUs. The video also explores advanced features such as creating multiple scenarios, editing PDUs, and viewing packet details. Additionally, it demonstrates how to use the challenge mode to test your understanding of the OSI model, making it a valuable resource for networking learners.

Takeaways

• 🕰️ In real-time mode, the time runs continuously, while in simulation mode, time can be stopped, slowed down, or controlled manually.
• 🔍 The simulation panel allows users to monitor network traffic, viewing one packet at a time.
• ⏯️ The forward, play, and back buttons control the movement of packets within the simulation panel step-by-step or automatically.
• 🔄 Power cycling restarts all devices, clearing the event list and requiring configurations to be saved beforehand.
• ⚡ The animation speed in simulation mode can be adjusted using a slider, affecting how fast packets are forwarded.
• ⏲️ The constant delay feature ensures consistent transmission and propagation times, which can be toggled off for variable delays.
• 📊 The edit filter option allows users to choose which protocols are visible in the simulation panel without removing them from the network.
• 🌐 Users can create ACL filters to control the visibility of specific packet types, such as permitting or excluding protocols.
• 💻 The complex PDU feature allows detailed control over packet creation, including source, destination, sequence numbers, and size.
• 🧑‍🏫 The OSI model tab in the PDU information window helps users understand how packets are processed at each network layer.

Q & A

What is the difference between real-time mode and simulation mode in Packet Tracer?

In real-time mode, time runs continuously, and the network functions as it would in reality. In simulation mode, time is stopped and can be controlled by the user to observe network traffic in detail, packet by packet.

How do you control the speed of a simulation in Packet Tracer?

The speed of a simulation can be controlled using the slider in the simulation mode. Dragging the slider to the right speeds up the simulation, while dragging it to the left slows it down.

What happens when the 'Power Cycle devices' option is selected?

When the 'Power Cycle devices' option is selected, all devices in the network are restarted, and the event list is cleared. It's important to save any running configurations to avoid losing unsaved changes.

What is the purpose of the 'Edit Filter' in Packet Tracer?

The 'Edit Filter' allows users to control which protocol events are visible in the simulation panel. Disabling a protocol in the filter does not stop it from propagating on the network, but it hides it from view.

What does the 'constant delay' option do in Packet Tracer?

When 'constant delay' is enabled, the transmission and propagation delay between packets is kept consistent. Disabling it allows for varying delays between packets.

What is the 'user created packet window' used for?

The 'user created packet window' allows users to view and manage scenarios where they have created specific packets for testing. It also enables the creation of multiple scenarios without losing previous ones.

What is the purpose of creating a complex PDU in Packet Tracer?

A complex PDU allows for detailed customization of packet transmission, including defining the packet's size, time-to-live (TTL), sequence number, and the interval at which the packet is sent.

What does the 'Type of Service' field represent in the IP header?

The 'Type of Service' field in the IP header represents the quality of service (QoS) for the packet, indicating how the packet should be handled in terms of priority across the network.

How does the 'challenge mode' in Packet Tracer help users?

The 'challenge mode' tests the user's understanding of the OSI model by asking questions about each layer. It provides hints and immediate feedback on correct and incorrect answers.

What happens when you 'reset devices' in Packet Tracer?

When devices are reset, the simulation starts from scratch, clearing the event list and reinitializing network services like HTTP. It's important to save configurations before resetting.

Outlines

00:00

🚀 Introduction to Packet Tracer Simulation Modes

The video begins with an introduction to the Packet Tracer environment, specifically focusing on the simulation and real-time modes. In real-time mode, the network runs continuously, indicated by a clock. Switching to simulation mode stops the time, allowing users to control and observe network traffic at a detailed level. The simulation panel provides features to control the speed of time, step through events, and play or pause the simulation. The episode also discusses how to add a Ping PDU and the importance of saving configurations before restarting devices.

05:01

📊 Controlling Packet Tracer Simulation Speed and Filtering Events

This section explains the control of animation speed in Packet Tracer's simulation mode, demonstrating how dragging the slider affects the speed of the simulation. It then covers resetting the simulation to observe speed changes and introduces constant delay, which can be enabled or disabled to control packet transmission delays. The user can also use filters in the simulation panel to control which network events are visible, with the ability to customize the view by selecting or excluding different protocols.

10:03

🔄 Creating and Managing Scenarios in Packet Tracer

Here, the video shows how to create and manage multiple scenarios within a Packet Tracer project. The user can create a test scenario without losing the previous one, allowing for multiple simulations on the same topology. The speaker demonstrates a ping between two devices and explains how packet events are displayed in the simulation. The discussion includes viewing Quality of Service (QoS) stamps, which indicate special handling of packets, and how these marks can be toggled on and off in preferences.

15:06

🔧 Creating Complex PDUs and Customizing Packets

This segment dives into creating complex PDUs in Packet Tracer. The user can define source and destination IP addresses, the TTL (Time to Live), the sequence number, and packet size. The video details how to configure periodic intervals for sending packets and how to modify or delete PDUs after creation. The speaker also shows how to change the color of PDUs for better visualization and explains the distinction between simulation time and the event list's time.

20:08

🧩 Understanding the PDU Information Window and OSI Model

The final part of the video covers the PDU information window, which provides details about packet processing at each OSI layer when clicking on packet events in the simulation. The video explains how incoming and outgoing layers are displayed, as well as the inbound and outbound PDU details, showing header fields and packet status. Additionally, the challenge mode is introduced, where users answer questions about the OSI model to test their knowledge. If the user answers correctly, they can proceed to the next layer.

Keywords

💡Simulation Mode

Simulation Mode in Packet Tracer allows users to stop real-time actions and control the flow of time in the network environment. It helps users observe and analyze network traffic in detail by slowing down or stepping through events one at a time. In the script, the simulation mode is demonstrated when the speaker shows how network traffic can be viewed one packet at a time and how different time controls (e.g., forward, play, backward) are used.

💡Real Time Mode

Real Time Mode is the default mode in Packet Tracer where time runs continuously, simulating a live network. This mode reflects real-world network behavior as events happen instantaneously. In the script, the speaker starts by explaining that in real-time mode, the clock keeps running, and all network actions happen as they would in a real network environment.

💡PDU (Protocol Data Unit)

A Protocol Data Unit (PDU) refers to a packet of data transmitted across a network. In Packet Tracer, PDUs can be created to simulate communication between devices. The video demonstrates the creation of a simple ping PDU from PC0 to Server0, allowing users to see how packets are processed and forwarded between network devices.

💡Event List

The Event List is a feature in Packet Tracer’s simulation panel that logs network events and displays packets as they are processed. Users can interact with this list to view detailed information about each event, control the flow of time, and observe the results of network transmissions. The script shows how the event list helps track packet movements and allows users to step through network events.

💡ACL Filter

An Access Control List (ACL) Filter in Packet Tracer is used to control which network protocols or packets are visible during a simulation. While the packets are still transmitted, the filter determines if they are displayed to the user. The video demonstrates how to create and apply ACL filters, showing how users can control which events or packets they see in the simulation panel.

💡Constant Delay

Constant Delay in Packet Tracer refers to a setting where the transmission and propagation delay for packets remains the same throughout the network. The script explains the difference between constant and variable delay and shows how enabling constant delay results in more uniform transmission times, as opposed to fluctuating delays when the feature is disabled.

💡Quality of Service (QoS)

Quality of Service (QoS) is a networking concept that prioritizes certain types of traffic to ensure higher performance for specific services. In Packet Tracer, packets marked with a QoS stamp have higher priority. The video describes how users can toggle the visibility of QoS marks in the simulation and view the type of service field set in the IP header for certain packets.

💡Complex PDU

A Complex PDU is a customized packet that can be configured with various settings, such as source and destination IP addresses, packet size, and transmission intervals. The script walks through the process of creating a complex PDU in Packet Tracer, explaining how to define specific parameters like time to live (TTL) and sequence numbers for more advanced simulations.

💡OSI Model

The OSI (Open Systems Interconnection) Model is a framework that defines how data is transmitted through different layers of a network. In Packet Tracer, the OSI model is represented in the PDU Information Window, where users can see how packets are processed at each layer (e.g., physical, network, transport). The video highlights how this feature helps visualize the packet’s journey through the network.

💡Challenge Mode

Challenge Mode in Packet Tracer is a feature that quizzes users on their understanding of network layers and the OSI model. The user is presented with questions related to each layer, and their knowledge is tested through interactive scenarios. The video shows an example of using Challenge Mode, where the user answers questions about how packets are processed at different OSI layers.

Highlights

Introduction to Packet Tracer's simulation environment, covering both real-time and simulation modes.

Explanation of real-time mode where time runs continuously, shown by a clock.

In simulation mode, time can be controlled manually, useful for detailed network traffic observation.

The simulation panel allows controlling time by playing, forwarding, or rewinding steps during simulation.

Power cycling devices clears the event list and restarts all devices, requiring configurations to be saved beforehand.

Ping commands are used to demonstrate packet creation between devices like PC0 and server.

In simulation mode, the time slider adjusts the speed of time flow and animation.

Constant delay option maintains uniform transmission and propagation delays between packets.

Edit filter feature allows users to hide or show network protocol packets in the simulation, without affecting their propagation.

Advanced ACL filter creation process, including a step-by-step guide for setting up filters for specific network traffic.

Creation of multiple simulation scenarios that can run simultaneously for different test environments.

The simulation panel displays packet events in real-time, including packet creation and progress.

Detailed explanation of the PDU (Protocol Data Unit) window, showing the OSI model, inbound, and outbound details for each packet.

Challenge mode tests knowledge of the OSI model, providing hints and feedback on correct or incorrect answers.

Explanation of complex PDU creation, allowing for customized packet configurations with options for TTL, sequence numbers, and packet size.

Transcripts

hello and welcome to this episode of

Packet Tracer in this episode we want to

have a brief introduction of simulation

environment so let's get started

so by default we are usually in real

time mode and in real time mode the time

is running continuously and it's

indicated by this clock

if we switch to the simulation mode the

time stops

and the simulation mode is used to

observe Network traffic and detail and

time can be directly controlled by us

the user

in the simulation mode we can stop or

slow down time to allow us to view data

traffic one packet at a time

let's add a simple pdu a ping pdu from

pc0 which is the source to server zero

which is the destination

now you can see that the packets has

started appearing here in the simulation

panel

in the simulation panel we can control

Time by going forward one step at a time

to continuously play time and to go

backward

these controls are also available in

here for us in the simulation toolbar

we also have the ability to hide the

simulation panel so if I click event

list the simulation panel will disappear

and if I click on it once again the

simulation panel will appear once again

the forward button will forward

simulation one step at a time the play

button will automatically show and run

events

and if we click on the back button the

back button can be used to view packets

that occurred on a previous time frame

if I click on play once again

the time will stop or pause

if I click on Power Cycle devices all of

the devices will be restarted and

the event list will be cleared

and all these startup processes such as

HTTP will initialize once again and you

need to save any configurations before

restarting the devices so if you haven't

copied your running config to the

startup config you need to do the so

otherwise you will lose your

configuration

we can click on no to cancel the power

cycle of devices

and that's it for this episode everyone

I hope this has been informative for you

and I would like to see you in the next

episode hello and welcome to this

episode of package racer in this episode

we want to discuss a few features of the

simulation panel so let's get started

first we want to create a packet from

pc0 to server zero

as you can see here in the simulation

panel we have these buttons the play

button will run the time in simulation

mode and packets will start forwarding

the forward button will forward the

packets one step at a time and the back

button will return to a previous time

frame

now let's play this simulation

this slider controls the speed of the

animation and the speed of the time in

the simulation mode and if we drag it to

the right side the time will flow faster

and if we drag it to the left side the

time will be slower

now let's reset the simulation so you

can see the effect of the slider if I

bring it to the left side the time will

be very slow and you can see that the

animation is very slow now I'm dragging

it to the right side now you will see

that the animation will be much faster

now if I click on the play button once

again the simulation time has stopped

and this is the time when the last

packet has happened in the simulation

this time is specific to the simulation

panel and it shows the time relative to

the last time that the simulation was

restarted and it is very different from

the time that's running in here

the last device shows the previous

location of the packet and the add

device shows the current location of the

packet as you can see the packet is

currently at pc0 and the type obviously

specifies the type of packet

we also have this constant delay if we

have this constant delay enabled the

transmission and propagation delay will

be constant but if we remove it the

transmission and propagation delay will

be different let me show you how

let's enable constant delay

and let's restart the devices so our

packets are created

now you can see that delay between each

of the packets are quite constant it's

almost one millisecond and if I remove

the constant delay and restart the

devices once again

now play the simulation mode

you can see that the time

frame between each packet is different

between these packets it's almost 2

milliseconds but now C in this packet

it's one millisecond and that's how the

constant delay make sure that the

transmission and propagation delay is

constant

the edit filter will allow us to control

which events will be visible in the

simulation panel let's go to the edit

filter

we have four tabs in the edit filter

window ipv4 IPv6 and miscellaneous

and various Protocols are categorized

under these tabs ipv4 IPv6 and

miscellaneous

if we add or remove some protocols from

the filter that doesn't mean that these

packets will disappear from the network

these packets will still be on the

network but they just won't be visible

so if I remove ospf

that means that the ospf packet will

still propagate in the network but it

will not be visible to me

let's go to the edit ACL filters

here we can create ACL filters and let

me create a new ACL filter and give it

a name

let's start by permit

space

IP

Annie

Annie

and as you can see I also have the

context help available

once the carriage return is shown to me

that means that my ACL filter is almost

at the end so I can submit it

and now this statement is added

now let's close this window

and close this window as well

you will be able to see that the in the

event list filters I have my all allow

filter

now let's go and delete that filter

now that filter is gone

we have the ability to show all the

filters or exclude all of the filters

with this button

now that I have all of the filters

enabled I can exclude one or two

or maybe when I don't have any of the

filters enabled then I can include one

or two

and that's it for this episode everyone

I hope this has been informative for you

and I would like to see you in the next

episode hello and welcome to this

episode of Packet Tracer in this episode

we want to discuss about some Advanced

features of simulation mode so let's get

started

here I want to click this arrow and I

want to open this area this area is

called the user created packet window I

have the ability to switch between

different scenarios

scenarios allow you to play with a

topology with different ways for example

I have a different

packet created on this topology on

scenario zero and then I don't want to

lose that and I want to create another

scenario I will call it my

test scenario

and then I can create other type of

packets on the test scenario and I will

be able to have both of these scenarios

available to me at the same time

now let's go to this window and add some

description for scenario one or my test

scenario let's call it test scenario

description

now let's close this window

now I want to Ping pc1 from pc0 let me

write the IP addresses for you so it

makes it easier for you to understand

this is 1.1 and this is 192.168.1.2

let me open PC zero

and issue a ping command

paying 192 168 1.2

now you could see that the Ping package

has appeared in here in the event list

even though they have not appeared in

the user created packet window

if I forward this simulation a little

bit and samping commands are created you

will be able to see that I can see in

real time the result of my ping commands

let's go a bit further more

as you can see my ping command was

successful

now let's close this window and see a

few other packets

now as you can see the quality of

service router has created a packet that

has a small square mark on top of the

packet this is called the quality of

service stamp and it means that the type

of service field is set in the IP header

for this packet

we can change the ability to view this

type of quality of service marks or to

disable this type of quality of service

Marks here in the preferences and if I

come to show quality of Service stamps

on packets if I play with this option

you can see that this Mark can appear

and disappear

I wanted to show all the time so I will

click on show and close preferences

now let's go and create a complex pdu I

can create a complex video by coming to

here and add and clicking on the add

complex pdu icon once I've clicked to

the add complex video icon my cursor

will change and I can click on the

source device

and this window will appear for me

now this is the source device and I can

choose the outgoing port or Packet

Tracer will also Auto Select that port

for me

for my PC I don't have any other Port so

the Auto Select is good

I have the ability to change between

different type of applications but for

me ping is good

I want to enter the destination IP

address as well

I can do that by entering the

destination IP address using my keyboard

or I can also

click here on the destination device and

the address will appear for me

The Source IP address I want to leave it

blank because the fast ethernet zeros IP

address will be used by default

I can also Define the TTL or time to

live value for this ping packet

and I can additionally Define the type

of service field for this IP packet

I need to add a sequence number because

this is mandatory and sequence numbers

are used for Ping packets or any other

packets that have been duplicated

dropped or re-ordered and the sequence

number is useful for such purposes

the size of packet I can Define the size

of packet as well well we forgot to have

the sequence number let's put let's put

one

the size of the packet I can Define the

size of the packet in bytes usually it's

32 bytes but I want to create it a

hundred byte

we can send this complex pdu at one shot

at a specific time we can specify the

time or we can specify a periodic

interval that the pdu will be sent

remember that this time

is related to the time in the event list

and it's not related to this time in

here

let's create an interval of 5 Seconds

and create a video

now as you can see the pdu has appeared

in the user created pdu window I can

toggle this pdu list window and a better

view is shown to me

if I double click on the fire field

this pdu will be created and will be

sent

the last status will show the status of

the pdu packet if it is in progress or

it has failed or it has succeeded The

Source obviously shows the source device

and the destination shows the

destination device

the type shows the type of protocol that

we are using and the color is an

indicator of the color here in the

workspace

I don't like this color so I can change

it

if I double click on the color then I

can change to another color let's select

black because I like black

and let's click ok

now you can see that

the color has changed and it has also

changed here in the simulation on the

animation and it has also changed in

here in the event list

the time here is the time interval and

the period shows whether this pdu is

created for for intervals yes or no

the number shows the sequence of this

pdu

and we can edit this pdu once again if I

double click on the edit

or I can delete this pdu all together by

double clicking the delete

now the pdu is completely deleted

now I want to toggle back this PDO list

window to its place

and delete our test scenario

and we go back to our scenario 0 which

is the default scenario

and that's it for this episode everyone

I hope this has been informative for you

and I would like to see you in the next

episode hello and welcome to this

episode of Packet Tracer in this episode

we want to talk about pdu information

window so let's get started

first I want to go to the simulation

mode and here I am in the simulation

mode and I have my simulation panel let

me create some ping packets from one

device to another so that some traffic

is generated and my event list is

populated as you can see my event list

is populated and I can see the packets

here in the animation and also the

packets here the in the event list and

if I click on any of them here in the

animation or if I click here on top of

the event list packet

this pdu information window will appear

for me

in the pdu information window we usually

have three tabs but now for this packet

we have two tabs which is the OSI model

and the outbound pdu detail

now let's move forward these simulation

so we can have a packet that will have

all the three tabs

now in here we have this packet which

has the OSI model the inbound pdu

details and the outbound pdu details

here in the OSI model tab the pdu

information window is showing the

information on how this packet is being

processed at each layer of Packet Tracer

by the device

you can see that we have some

information such as ADD device which

means that this packet is located here

in R3 the source of the device was this

router and the destination of the device

was the artery itself

we have the incoming layers and the

outgoing layers the incoming layers they

show us how this packet is being

processed when it's received at this

device and the outgoing layers it shows

us the decisions that this device has

taken to forward this message this

packet out of its Sports

for incoming layers we need to start

from bottom to and go to the top and for

the outgoing layers we can start from

the top and go to the bottom

if I click on each layer then additional

information about that layer will appear

for me in here

or I can click on this previous layer or

next layer buttons

in the inbound pdu information there is

some information about the pdu type and

the IP header and Fields that is

available on this packet when it was

received and the outbound pdu detail is

showing the similar information but when

this packet is going to be sent out of

one of the ports

now let's go back to the OSI model

and let's go to the challenge mode

the challenge mode will challenge you on

your understanding of the USI model and

will give you a few questions about each

layer of the OSI model

I have been given a question and I have

the ability to have a hint if I click

hint a hint will appear for me in here

if I click the hint again this window

will disappear and if I hover my mouse

over this answers some hands will appear

for me as well

now let's select an answer

and click the next layer so we can

process our answer was correct so it

went to the next layer now let's I have

the same answer click on next layer and

my answer was correct and that's why I

was able to move to layer 3. now if I

click on next layer my answer is not

correct and that's why I cannot move

further let me resize this window

so that you can see I'm not sure why

this area is not resizing but it's

supposed to tell us that the answer is

not correct

once I've answered all of the questions

I will get this message congratulations

I have successfully completed this

Challenge and that's it I can close the

challenge mode

and that's it for this episode everyone

I hope this has been informative for you