A straight-through cable is the standard network cable connection and is used to connect the source and destination computers over the Internet. With a crossover cable, the standard RJ-45 cable is cross-connected between the source and target computer. A rollover cable (8-pin) usually has RJ-45 connectors on both ends that are used to connect router and computer ports.
A rollover cable with an RJ-45 connector is used to connect the PC or terminal to the console port of the Cisco device. Then connect the other end of the console or rollover cable to the RJ-45 to DB-9 or RJ-45 to DB-25 adapter, depending on the available PC serial port. Bridge: A device that connects multiple network segments along the data link layer operates at OSI layer 2.
So unlike a hub, a switch splits network traffic and sends it to different destinations instead of all systems on the network. Operates at OSI layer 2. When using a hub, everyone has connected all objects compared to switches that provide a dedicated connection between individual nodes. Operates at OSI layer 1. Multilayer switch: A switch that provides functionality at higher layers in addition to switching to OSI layer 2 protocol.
Bridge Router (Router B): combines the functionality of a router and a bridge and therefore operates at OSI Layers 2 and 3. Hardware or software components that are usually located at the connection point of different networks, e.g.
OSI Model and TCP/IP Practical Visual Simulation In Packet Tracer
Objectives
Interaction of Protocols
Often, many of the protocols that comprise a protocol suite refer to other widely used protocols or industry standards. HTTP defines the content and formatting of the requests and responses exchanged between the client and the server. Both the client and the web server software implement HTTP as part of the application.
TCP breaks the HTTP messages into smaller pieces, called segments, to be sent to the destination client. A layered model shows the operation of the protocols that occur within each layer, as well as the interaction with the layers above and below it. Helps with protocol design because protocols operating at a specific layer have defined information on which they act and a defined interface to the layers above and below.
The TCP/IP model is a protocol model because it describes the functions that occur at each protocol layer within the TCP/IP suite. A reference model is not intended to be an implementation specification or to provide a sufficient level of detail to precisely define network architecture services. The main purpose of a reference model is to aid in clearer understanding of the functions and process involved.
Ultimately, designers are required to communicate with industry by relating their product or service to either the OSI model or the TCP/IP model, or both. At each stage of the process, the PDU has a different name to reflect its new appearance. Although there is no universal agreement on naming PDUs, in this course PDUs are named according to the protocols of the TCP/IP suite.
In the web server example, we can use the TCP/IP model to illustrate the process of sending an HTML web page to a client. The application layer protocol, HTTP, starts the process by delivering the HTML-formatted web page data to the transport layer. The IP packet is then sent to the Network Access layer Ethernet protocol, where it is encapsulated in a frame header and trailer.
Server to client communication
- Examine the Help Files and Tutorials
- Switching from Realtime to Simulation Mode
- Creating a Packet and Accessing the PDU Information Window
- Investigating device algorithms in the OSI Model view
- Inbound and Outbound PDUs
- Packet tracing: animations of packet flow
- Connect S1 and PC1
- Change to global configuration mode
- Configure S1 as the hostname
- Change to interface configuration mode for Fa0/18
- Set the port mode to access
- Exit interface configuration mode
- Enter configuration mode for the console line
- Enter cisco as the password
- Return to privileged EXEC mode using the end command
- Use Help Facility to Configure the Clock
- At the privileged EXEC command prompt, type clock?
- Use Help to assist setting the clock to the current time
- Verify that the clock is set
- View the most recent commands entered
- Change the number of commands stored in the history buffer
- Verify that the size of the history buffer has changed
- Check which Cisco IOS software version is currently loaded
- Check which Cisco IOS images are loaded in flash memory
- Check the MAC address of the server
- Configure static MAC for the TFTP server
- Verify that the static MAC address is now in the MAC address table
P a g e | 24 On the lower right side of the PT interface is the toggle between real-time and simulation mode. Two packages appear in the event list, one of which has an eye next to it. Find the first package in the event list and click the colored square in the Info column.
When you click the Info square for a package in the event list, or click a package envelope displayed on the logical topology, the PDU information window opens. In the case of the first package we're looking at, you'll see the HTTP request (at layer 7) being encapsulated in layers 4, 3, 2, and 1 sequentially. See what happens at each layer - this will be the subject of much of the rest of the course.
This activity focuses on navigating command line interface modes, using utility functions, accessing command history, configuring boot sequence parameters, setting speed and duplex settings, and managing the MAC address table and switch configuration file. Use a console cable to connect the RS 232 interface on PC1 to the console interface on switch S1. In addition to the basic monitoring commands, configuration and administration commands are now accessible.
5BcL
When you configure a VLAN, you can name it to describe the users' primary role for that VLAN. As another example, all student computers in a school can be configured in the "Student" VLAN. Using VLANs, you can logically segment switched networks based on functions, departments, or project teams.
You can also use a VLAN to structure your network geographically to support businesses' growing reliance on remote workers. In order for computers to communicate on the same VLAN, each computer must have an IP address and subnet mask that is consistent across that VLAN. The switch must be configured with the VLAN and each port in the VLAN must be assigned to the VLAN.
Remember, just because two computers are physically connected to the same switch doesn't mean they can. Devices on two separate networks and subnets must communicate via a router (Layer 3), regardless of whether VLANs are used or not. You don't need VLANs to have multiple networks and subnets on a switched network, but there are definite advantages to using VLANs.
Security - groups that have sensitive data are separated from the rest of the network, which reduces the chances of intrusion into confidential information. As explained in the "Switch Configuration" section, LAN segmentation prevents a broadcast storm from spreading across the entire network. You can see in the figure that although there are six computers on this network, there are only three broadcast domains: Faculty, Student, and Guest.
Improve IT staff efficiency - VLANs make it easier to manage the network because users with similar network requirements share the same VLAN. It is also easier to determine the extent of the effects of upgrading network services. A VLAN trunk does not belong to a specific VLAN, rather it is a channel for VLANs between switches and routers.
- Display the current VLANs
- Verify connectivity between PCs on the same network
- Configure VLANs Step 1. Create VLANs on S1
- Create the VLANs on S2 and S3
- Verify the VLAN configuration
- Assign VLANs to the active ports on S2
- Assign VLANs to the active ports on S3
- Verify loss of connectivity
- Configure Trunking
- Configure S1 Fa0/1 and Fa0/3 for trunking and to use VLAN 99 as the native VLAN
- Verify trunking is enabled on S3 and configure VLAN 99 as the native VLAN
When you manually assign a switch port to a VLAN, it is known as a static access port. This activity focuses on creating and naming VLANs, assigning access ports to specific VLANs, changing the native VLAN, and configuring trunk links. From privileged EXEC mode on all three switches, issue the show running-config command to verify the current running configuration.
After creating the VLANs, switch to privileged EXEC and issue the show vlan brief command to verify the creation of the new VLANs. 10 Faculty/Staff active 20 Students active 30 Guest(Default) active 99 Management&Native active 1002 fddi-default active 1003 token-ring-default active 1004 fddinet-default active 1005 trnet-default active S1#. On S2 and S3, use the same commands you used on S1 to create and name the VLANs.
The range command greatly reduces the amount of repetitive commands you must enter when configuring the same commands on multiple ports. S2(config)#interface fastEthernet 0/6 S2(config-if)#switchport mode access S2(config-if)#switchport access vlan 30 S2(config-if)#interface fastEthernet 0/11 S2(config-if)# access switch mode S2(config-if)#access switch vlan 10 S2(config-if)#interface fastEthernet 0/18 S2(config-if)#access switch mode S2(config-if)#access switch vlan 20. S1( config-if)#switchport trunk source vlan 99 S1(config-if)#interface FastEthernet 0/3 S1(config-if)#switchport mode trunk.
However, DTP has negotiated trunking, so the operating mode is trunk, resulting in a native VLAN mismatch. To correct the native VLAN mismatch, configure the trunking port with the switchport trunk native vlan 99 command.
