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Cisco Packet Tracer 8.x tutorials

Introduction

Frame Relay is a protocol standard for WAN internetworking which provides a fast and efficient method of transmitting packets through the network. Frame Relay offers an attractive alternative to both dedicated lines and X.25 networks for WAN links. The success of the Frame Relay protocol is based on the following two factors:

  • Virtual circuits consume bandwidth only when they transport data. Consequently, many virtual circuits can exist across a given transmission line, which is an improvement compared to dedicated leased lines. In addition, each device can use more than the allowed bandwidth as necessary, and thus operate at higher speeds.
  • The increased error-handling sophistication at end stations and the improved reliability of communication lines allows the Frame Relay protocol to discard bad frames and thus eliminate time-consuming error-handling processing.

Cisco Packet Tracer 8.2 includes a "Cloud-PT" device for WAN emulation. This device can be configured as a Frame Relay switch.  Router are connected to the Frame Relay switch using serial connections. Virtual circuits, LMI types, and DLCI are configured using the Serial and Frame Relay tabs of the "Cloud-PT" device.

 

Introduction

Access Control Lists (ACL) are used to filter network traffic on Cisco routers. In order to filter network traffic, ACLs control if routed packets have to be forwarded or blocked at the ingress or egress router interface. The router checks each packet to determine whether to forward or drop the packet based on the criteria specified in the ACL applied to the interface.

Cisco Wireless concepts

The Cisco Wireless Controller (WLC) devices is the Cisco solution to centrally configure, manage enterprise wireless networks, regardless of the number of access points deployed and thei location. Wireless controllers have become very popular as companies move from standalone Access Point (AP) wireless designs, complicated to configure and to secure properly, to centralized controller-based designs, reaping the enhanced visibility, functionality and redundancy benefits that come with those modern designs.

The following youtube video presents the basic concepts of how Wireless Controllers work and interact with Lightweight access points using CAPWAP protocol. A good understanding of the concepts presented in this video is mandatory before starting this Packet Tracer 8.2 wireless tutorial.

 

The Link Layer Discovery Protocol (LLDP), standardized as 802.1AB, is a standardized network discovery protocol aimed to replace a wide variety of propietary protoclos such as Cisco CDP, Nortel discovery protocol, ... It helps network administrators to identify the neighbors devices (including remote ports) of the device they are configuring. As a link-layer protocol, LLDP works without needing a valid IP configuration on the devices.

What is Precision Time Protocol (PTP) ?

Precision Time Protocol (P2P) is a feature of Packet Tracer 8.2 available in IE2000 industrial switches.

This time synchronization protocol is defined in IEEE-1588 as Precision Clock Synchronization for Networked Measurements and Control Systems, and was developed to synchronize the clocks in networks devices that include distributed device clocks with various levels of precision and stability. Acurate time synchronization is vital for smart grid power automation applications such as virtual power generators and peak-hour billing, but also for network outage monitoring tools which require a high level of time accuracy and stability.

 

PTP configuration in Packet Tracer 8.2

Precision Time protocol can be simulated in Packet Tracer 8.2 using IE2000 switches. These switches features three PTP modes :

  • boundary
  • end-to-end transparent
  • forward.
Switch(config)#ptp mode ?
  boundary        Boundary Clock mode
  e2etransparent  End-to-End Transparent Clock mode
  forward         Forward packets without processing

 

1.Configure PTP using the following commands

Switch(config)#ptp mode boundary 
Switch(config)#interface fastEthernet 1/1
Switch(config-if)#ptp enable

2. Verify PTP global configuration using the show ptp clock command

 Switch#show ptp clock
 PTP CLOCK INFO
  PTP Device Type: Boundary clock
  PTP Device Profile: Default Profile
  Clock Identity: 0x00:50:0F:FF:FE:0A:9D:00
  Clock Domain: 0
  Number of PTP ports: 10
  Priority1: 128
  Priority2: 128
  Clock Quality:
        Class: 248
        Accuracy: Unknown
        Offset (log variance): N/A
  Offset From Master(ns): 0
  Mean Path Delay(ns): 0
  Steps Removed: 0
  Local clock time: 01:51:07 UTC mars 30 2011 
 
 

3. Verify the fastethernet 1.1 configuration using the show ptp port IOS command to make sure PTP clock is forwarded on the network interface.

Switch#show ptp port 
 PTP PORT DATASET: FastEthernet1/1
  Port identity: clock identity: 0x00:50:0F:FF:FE:0A:9D:00
  Port identity: port number: 1
  PTP version: 2
  Port state: MASTER
  Delay request interval(log mean): 5
  Announce receipt time out: 3
  Announce interval(log mean): 1
  Sync interval(log mean): 0
  Delay Mechanism: End to End
  Peer delay request interval(log mean): 0
  Sync fault limit: 500000000

 

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