What is Routing?
Routing is like finding the best way for information (data) to travel from one place to another in a computer network. Just like a map helps you find the right road to reach your destination, routers help data find its way from the source (where it starts) to the destination (where it needs to go). Routers are like smart traffic controllers for data in networks.
What is the purpose of the Data Link layer?
The Data Link layer is like a communication manager for devices in a network. Its main job is to make sure that messages are sent to the correct device. It does this by putting addresses on the messages so they go to the right place. Another thing it does is "framing," which means putting the data into a neat package before sending it.
What is the key advantage of using Switches?
Switches are like super-fast mail sorters for data in a network. When they get a message, they quickly figure out where it needs to go and send it directly to that place, instead of sending it everywhere. This makes data transmission really efficient and fast.
When does Network Congestion occur?
Network congestion happens when there are too many users trying to use the same internet "road" (bandwidth) at the same time. It's like a traffic jam on the internet highway. This can happen in big networks that don't divide themselves into smaller parts.
What is a Window in networking terms?
In networking terms, a "Window" is like a box that holds a certain number of data pieces (segments) that can be sent from one place to another before asking for confirmation. It's like a delivery person taking multiple packages at once and then getting a receipt for all of them together.
Does a bridge divide a network into smaller segments?
No, a bridge doesn't divide a network into smaller parts. Instead, it acts like a filter that lets certain data pass through while blocking other data. It helps to manage the flow of information in a network without changing its overall size.
Which LAN switching method is used in CISCO Catalyst 5000?
The CISCO Catalyst 5000 uses the "Store-and-forward" switching method. This means that when it receives data, it first checks if the data is complete and accurate before sending it along to its destination. It's like making sure a letter is correctly addressed and stamped before mailing it.
What is the role of the LLC sublayer?
The LLC sublayer (Logical Link Control) helps with special services for applications in a network. It can provide things like controlling the flow of data and correcting errors to make sure information is sent and received correctly. It's like having a special assistant to take care of important tasks for the network.
RIP vs. IGRP:
RIP and IGRP are both routing protocols used in computer networks. They help routers decide the best path to send data from one place to another. The main difference between them is how they make this decision.
- RIP: It decides the best route based on the number of "hops" (like jumping from one router to another) to reach the destination network. It's a simple approach but may not always find the most efficient path.
- IGRP: Unlike RIP, IGRP considers various factors before choosing the best route. It looks at things like bandwidth, reliability, MTU (Maximum Transmission Unit), and hop count. This makes IGRP more sophisticated and often leads to better routing decisions.
A CISCO router has different types of memory to store essential information.
Application Layer in Networking:
- NVRAM: It stores the startup configuration file, which contains settings and instructions for the router when it starts up.
- DRAM: This memory holds the configuration file that is currently being used by the router while it's running.
- Flash Memory: It stores the Cisco IOS, which is the operating system software that runs on the router and controls its functions.
BootP:
BootP (Boot Protocol) is a protocol used to help computers or devices that don't have their own storage (diskless workstations) to boot up and connect to a network. It helps these devices find their IP address and also the IP address of the server they need to communicate with.
The Application Layer is an important part of networking that deals with supporting communication for various applications (like web browsers, email clients, etc.). It provides network services that go beyond the standard specifications of the OSI reference model. It also helps in synchronizing applications on the server and the client devices.
User Mode vs. Privileged Mode:
When using a CISCO router, there are two modes of operation with different capabilities:
- User Mode: This mode is used for regular tasks such as viewing system information, connecting to remote devices, and checking the router's status. It has limited options.
- Privileged Mode: In this mode, you have access to all the options available in User Mode, and many additional ones. You can use Privileged Mode to make configurations on the router, perform tests, and do debugging.
100BaseFX is a type of Ethernet network that uses fiber optic cables as the primary transmission medium. The "100" refers to a data speed of 100 Megabits per second (Mbps).
These terms describe how devices communicate on a network.
- Full-Duplex: In this mode, both the sending and receiving devices can communicate simultaneously. They can transmit and receive data at the same time, allowing for faster and more efficient communication.
- Half-Duplex: In contrast, devices in half-duplex mode can either transmit or receive data at a given moment, but not both simultaneously. This can result in slower communication compared to full-duplex mode.
What is MTU?
MTU stands for Maximum Transmission Unit. It's like the maximum size limit for data packets that can be sent on a network without breaking them into smaller pieces.
How does cut-through LAN switching work?
Cut-Through LAN switching quickly sends data frames to the next network segment without waiting to check everything inside the frame. It's like forwarding a letter without fully reading its contents.
What is latency?
Latency measures the time it takes for a network device to receive a data frame and then send it to another network segment. It's like the delay between receiving and forwarding a message.
Utilizing RIP, what is the limit for the number of hops?
With RIP (Routing Information Protocol), the maximum number of hops is 15. If the count goes beyond 15, it means the network is unreachable.
What is Frame Relay?
Frame Relay is a special type of communication used in wide area networks (WANs). It creates virtual circuits for data transmission, ensuring reliable connections between distant places.
How do you configure a Cisco router to route IPX?
To enable IPX routing on a Cisco router, you use the "ipx routing" command. Then, you configure each interface used in the IPX network with a network number and an encapsulation method.
What are the different IPX access lists?
There are two types of IPX access lists: Standard and Extended. Standard Access Lists only filter based on the source or destination IP address. Extended Access Lists use more criteria like ports, protocols, and sockets for filtering.
Explain the benefits of VLANs.
VLANs (Virtual Local Area Networks) bring lots of advantages! They allow us to group devices based on functions, hardware types, or protocols, instead of just physical location. This flexibility helps create separate networks without being restricted to where the devices are physically placed.
What is subnetting?
Subnetting is like dividing a large network into smaller parts. Each smaller part is called a subnet and has its own unique identifier. This helps manage and organize the network better.
What are the advantages of a layered model in the networking industry?
Using a layered model in networking has many benefits. One advantage is that it allows administrators to make changes in one layer without affecting the other layers. This specialization helps the networking industry progress faster. Also, troubleshooting problems becomes easier with a layered model.
Why is UDP favored over TCP?
UDP is preferred over TCP for certain tasks because it is less reliable and doesn't guarantee the order of data delivery. This makes it faster for some applications that don't need strict error checking and acknowledgments.
What are some standards supported by the Presentation layer?
The Presentation layer supports various standards to ensure data is presented correctly. For graphics, it supports standards like PICT, TIFF, and JPEG. For Video/Audio, it supports standards like MIDI, MPEG, and QuickTime.
What's the simplest way to remotely configure a router?
To remotely configure a router, the easiest method is to use the Cisco AutoInstall Procedure. However, for this to work, the router must be connected to the WAN or LAN through one of its interfaces.
What does the "show protocol" display?
The "show protocol" command on a router displays the routed protocols that are configured on the router, the address assigned to each interface, and the encapsulation method that was configured on each interface.
How do you depict an IP address?
An IP address can be represented in three ways:
- Using Dotted-decimal format, for example, 192.168.0.1
- Using Binary format, for example, 10000010.00111011.01110010.01110011
How do you go to privileged mode? How do you switch back to user mode?
To access privileged mode, you can simply enter the command "enable" on the prompt. This mode allows you to perform administrative tasks and configure the device. If you want to switch back to the regular user mode, just enter the command "disable".
What is HDLC?
HDLC stands for High-Level Data Link Control protocol. It is a specific type of communication protocol used by CISCO devices. It comes pre-configured as the default encapsulation method in CISCO routers.
How are internetworks created?
Internetworks are formed when multiple networks are interconnected using routers. The network administrator assigns a logical address to each network that connects to the router, allowing them to communicate with each other.
What is Bandwidth?
Bandwidth refers to the capacity of a communication medium to transmit data. It measures how much data can be sent through a transmission channel in a given amount of time and is usually measured in Kbps (kilobits per second).
How do Hold-downs work?
Hold-downs are a mechanism to prevent a downed network link from being quickly reinstated. They achieve this by removing the downed link from the regular update messages. Hold-downs use triggered updates to reset a timer, ensuring that the link is stable before it is reactivated.
What are packets?
Packets are the result of data encapsulation, where data is divided into smaller units and wrapped in different protocols according to the OSI layers. These packets, also known as datagrams, are then sent over a network.
What are segments?
Segments are sections of a data stream that originate from the upper OSI layers and are ready for transmission on the network. At the Transport Layer, segments are the logical units used for data transfer.
What are the benefits of LAN Switching?
Some advantages of LAN switching include:
- Full duplex data transmission and reception: LAN switches allow devices to send and receive data simultaneously, which enhances network performance.
- Media rate adaption: LAN switches can adjust data rates to match the capabilities of connected devices, optimizing data transmission.
- Easy and efficient migration: LAN switching provides a smooth upgrade path from older network technologies to newer, faster ones, without disrupting the network's functionality.
What is Route Poisoning?
Route Poisoning is a method used in computer networks to deal with inconsistent updates on a route. It involves adding a special entry with a value of 16 to a route, which makes it unreachable. By doing this, the network can avoid potential problems caused by incorrect or outdated route information.
How do you find valid hosts in a subnet?
To find the valid hosts in a subnet, you can use a simple equation. Subtract the subnet mask value from 256. The hosts that fall within this range are considered valid hosts for that subnet.
What is DLCI?
DLCI stands for Data Link Connection Identifiers. They are unique identifiers assigned by a frame relay service provider to each virtual circuit on the network. DLCIs help in distinguishing and managing the different connections within the frame relay network.
What are the different types of passwords used in securing a CISCO router?
There are five types of passwords used to secure a CISCO router. These are:
- Enable Secret: This password is used to protect privileged configuration mode.
- Enable: It is used to restrict access to the privileged mode.
- Virtual Terminal: This password secures remote Telnet access to the router.
- Console: This password safeguards access through the physical console port.
- Auxiliary: It secures the auxiliary port of the router, used for remote management.
Why is network segmentation a good idea when managing a large network?
Network segmentation is beneficial for managing large networks because it helps reduce network congestion and ensures that high bandwidth is available for all users. By dividing the network into smaller segments, data traffic can be efficiently managed, leading to improved network performance, especially as the network grows.
What are the things that can be accessed in a CISCO router's identifying information?
In a CISCO router's identifying information, you can access the following:
- Hostname: This is the name assigned to your router, which helps identify it on the network.
- Interfaces: These are fixed configurations that refer to the router ports, allowing you to manage connections and communication channels.
Differentiate Logical Topology from Physical Topology.
Logical Topology refers to the path that data takes through the network, describing how devices communicate and transmit data. On the other hand, Physical Topology refers to the actual layout and physical connections of the network, including devices, cables, and other hardware components.
In configuring a router, what command must be used if you want to delete the configuration data that is stored in the NVRAM?
When you're setting up a router and want to remove all the configuration information stored in the memory, you should use a specific command. The correct command to do this is "Erase startup-config." This will delete the configuration data that is saved in the NVRAM (Non-Volatile Random Access Memory), which is a type of memory that holds settings even when the router is turned off. So, to clear the router's saved configuration, use the command "Erase startup-config."
To make sure traffic is sent to the router correctly, you should use the following command on the branch router:
arduino(config-if)# dialer-group 1
This command helps to group the dialer interface with the dialer list, so it knows which traffic to permit. It ensures that the dialer interface will use the dialer list named "1" and permit IP protocol traffic.
When setting up a router and using both physical and logical interfaces, we need to figure out the OSPF router ID. The OSPF router ID is determined by considering the highest IP address of any logical interface. So, out of all the logical interfaces on the router, we look at their IP addresses, and the one with the highest IP address becomes the OSPF router ID. Now, let's talk about the differences between a switch, hub, and router:
- Hub: A hub is a simple device that allows multiple devices to connect to a network. It has a single broadcast domain and collision domain. When a device sends data to the hub, the hub sends that data to all the other connected devices. It doesn't make any intelligent decisions about where the data should go, which can lead to network congestion.
- Switch: A switch is more advanced than a hub. It filters and forwards packets between different parts of the local network (LAN segments). Switches have a single broadcast domain (like a hub) but multiple collision domains. They operate at the data link layer (Layer 2) and sometimes at Layer 3, supporting various packet protocols. Switches make intelligent decisions to send data only to the intended recipient, reducing network traffic and improving performance.
- Router: A router is a device that helps in transmitting data packets between different networks. It's like a traffic cop for data. When data needs to travel from one network to another, the router determines the best path and sends the data in the right direction. Routers operate at the network layer (Layer 3) of the networking model. They are essential for connecting different networks together, such as connecting your home network to the internet. So, in simple terms, a hub just sends data to all connected devices, a switch sends data only to the intended device, and a router helps in sending data between different networks.
What are data packets?
Imagine you want to send a big message to someone through the internet. But the internet can't handle large messages all at once. So, your message gets broken down into smaller pieces called "data packets." Each data packet includes important details like who sent it, who should receive it, and the actual message itself. It's like dividing your message into small envelopes, each with an identification number, so they can be easily sent and put together correctly on the other end.
What is DHCP?
DHCP is a computer thing called "Dynamic Host Configuration Protocol." It's like a helpful system that gives out addresses to different devices on a network. Just like how you have your own address to receive mail, devices like computers, printers, routers, and scanners need their unique "IP address" to communicate with each other on a network. DHCP automatically gives out these IP addresses to devices when they join the network. It's like a smart helper that makes sure everyone gets their address without you having to do it manually. You can also set up special, unchanging addresses for some devices, like printers and servers, if you want.
Dynamic IP vs. Static IP addressing:
- A dynamic IP address is like a temporary address assigned to your device by the network's DHCP server. It changes periodically or whenever you connect to the network. It's like getting a different seat on a bus every time you ride it.
- On the other hand, a static IP address is like having a fixed, permanent address for your device. It's manually set and doesn't change, just like having your own reserved seat in a theater. Private IP Ranges:
- There are three ranges for private IPs:
- Class A: Starts from 10.0.0.0 to 10.0.0.255.
- Class B: Starts from 172.16.0.0 to 172.31.0.0.
- Class C: Starts from 192.168.0.0 to 192.168.0.255.
Ways to access routers:
Routers can be accessed in three ways:
- Telnet (IP): Like giving instructions to a router through a phone call. AUX (Telephone): Similar to a backup phone line for communication with the router. Console (Cable): Connecting directly to the router using a cable, just like using a computer with a cable connection.
EIGRP (Enhanced Interior Gateway Routing Protocol):
- EIGRP is a special way for routers to share information about the best paths to send data within the same network system. It's like giving directions to different routers, but only telling them about new changes, not repeating everything all the time. EIGRP is made by Cisco Systems and helps routers work efficiently by reducing the amount of data they need to process.
Metrics of EIGRP Protocol:
- EIGRP protocol uses several factors to determine the best path for sending data. These factors are like different things considered while choosing the best route to a destination.
The metrics of EIGRP include:
- Bandwidth: How fast the route can transfer data.
- Load: How much traffic the route is currently handling.
- Delay: The time it takes for data to travel through the route.
- Reliability: How dependable and stable the route is.
- MTU (Maximum Transmission Unit): The largest data size the route can handle.
Clock Rate:
Clock rate is like a speed limit for the router interface, determining how much data can be sent in one second. It's similar to a traffic rule that controls how fast vehicles can go on a road.
