NetworkingMidterm.docx

**IP ADDRESSING** ================= - **IP (Internet Protocol)**: A fundamental protocol used to **uniquely identify** devices (nodes) on a computer network. - **IP Address**: A numerical label assigned to each device in a network, **enabling communication between devices**. - *...

**IP ADDRESSING** ================= - **IP (Internet Protocol)**: A fundamental protocol used to **uniquely identify** devices (nodes) on a computer network. - **IP Address**: A numerical label assigned to each device in a network, **enabling communication between devices**. - **Example**: 192.168.1.150 identifies a specific device on a network. **Types of IP Addresses** **1. IPv4 (Internet Protocol Version 4)** - **Format**: Four octets (parts) separated by dots, e.g., X.X.X.X. - **Range**: Each octet ranges from 0 to 255. - **Bit Length**: 32 bits. - **Example**: 192.168.1.150 or 10.0.0.1. **2. IPv6 (Internet Protocol Version 6)** - **Newer Version**: Designed to replace IPv4, with a much larger address space. - **Example**: 2001:0db8:85a3:0000:0000:8a2e:0370:7334. **Logical Addressing** IP addresses are logical, meaning they can be **changed based on location or network configuration** (unlike physical MAC addresses). They can be assigned: - **Manually (Static IP):** An IP address is **manually** assigned to a device. - **Dynamically (via DHCP): Automatically** assigns IP addresses to devices. **ROUTING PROTOCOLS** ===================== **Ways Routers Learn Routes** 1. **Static Routes** - **Connected/Directly Connected**: Routes identified through active interfaces. - **Manually Configured**: Administrators set static routes. - **Default Route**: Gateway of last resort for unknown destinations. 2. **Dynamic Routes** - Learned through routing protocols, exchanging information with neighboring routers. **Dynamic Routing Protocols** - **Role**: Exchange routing information, discover remote networks, determine best paths, update routes with topology changes. - **Benefits**: - **Adaptability**: Learns new routes, updates tables. - **Less Administrative Overhead**: Reduces manual configuration. - **Fault Tolerance**: Finds new routes if a link fails. - **Drawbacks**: - **Resource Intensive**: Requires CPU, memory, bandwidth. **Advantages of Dynamic Routing Protocols** - Automatic topology updates. - Less error-prone than static configurations. - Scalable for growing networks. **Disadvantages of Dynamic Routing Protocols** - Consumes router resources. - Requires more expertise for configuration and troubleshooting. **Static Routing** - **Suitable for**: Small networks, stub networks. - **Advantages**: - Minimal CPU processing. - Easy configuration for small networks. - More control over routing paths. - **Disadvantages**: - Time-consuming configuration and maintenance. - Error-prone for large/complex networks. - Requires manual intervention for changes. - Not scalable for larger networks. **Classifying Dynamic Routing Protocols** **Categories** 1. **IGP vs. EGP** - **IGP (Interior Gateway Protocol)**: **Within** an Autonomous System (AS) (e.g., OSPF, RIP). - **EGP (Exterior Gateway Protocol)**: **Between** different Autonomous Systems (e.g., BGP). 2. **Distance Vector vs. Link-State** - **Distance Vector**: Routes advertised by **distance** (hop count) and **direction** (e.g., RIP). Best for simple, flat networks. - **Link-State**: Routers share link-state info to build a complete network topology (e.g., OSPF). Best for large, hierarchical networks. 3. **Classful vs. Classless** - **Classful**: No subnet mask info (e.g., RIP v1, IGRP). - **Classless**: Includes subnet mask info, supports VLSM (e.g., RIP v2, EIGRP, OSPF). **Common Routing Protocols** - **RIP**: Distance vector, suitable for smaller networks. - **IGRP**: Cisco-developed distance vector (deprecated). - **OSPF**: Link-state, widely used in large networks. - **IS-IS**: Link-state, used in service provider networks. - **EIGRP**: Advanced distance vector by Cisco, supports classless addressing. - **BGP**: Path vector, used between Autonomous Systems. **Autonomous Systems (AS)** - **AS**: Collection of networks under single administrative control. - **IGP**: Operates within an AS. - **EGP**: Operates between Autonomous Systems. **Distance Vector vs. Link-State Protocols** - **Distance Vector**: Routes by hop count and direction, best for simple networks, slower convergence. - **Link-State**: Builds complete topology map, faster convergence, best for large networks. **Convergence in Dynamic Routing Protocols** - **Convergence**: When all routers have consistent routing tables. - **Faster Convergence**: Better performance in handling network failures or topology changes. **NETWORKING SWITCHING** ======================== **Switching**: Determines the **best route for data transmission** across a network, crucial for large networks like the Internet. **Types of Switching Techniques** **1. Circuit Switching** - **Dedicated Path**: Establishes a dedicated path between sender and receiver before data transmission. - **Phases**: - **Connection Establishment**: Path is set up. - **Data Transfer**: Data is transmitted. - **Connection Disconnection**: Path is terminated. - **Example**: Telephone networks. **2. Message Switching** - **Store-and-Forward**: Message is broken into pieces, stored at intermediary nodes, then forwarded. - **Complete Message**: Reconstructed at each node before forwarding. - **Not Suitable for Real-Time Applications**: Delays make it unsuitable for streaming or real-time communications (e.g., VoIP). **3. Packet Switching** - **Internet-Based**: Common in modern networks. - **Message Broken into Packets**: Each packet contains source and destination IP addresses and sequence numbers. - **Approaches**: - **Datagram Approach (Connectionless)**: Each packet is independent and may take different paths. - **Virtual Circuit Approach (Connection-Oriented)**: A pre-planned path is established, and all packets follow this path. **ROUTE REDISTRIBUTION** ======================== - **Route Redistribution**: Sharing routes learned from one routing protocol with another. **Use Cases** - **Expanding/Merging Networks**: Integrating different network segments. - **Transitioning Protocols**: Moving from one routing protocol to another. **Importance** - **Coexistence**: Necessary when multiple routing protocols are used within the same network. - **Network Reachability**: Ensures complete reachability across different protocols. **Redistribution Process**: 1. **RIP (Routing Information Protocol) to EIGRP (Enhanced Interior Gateway Routing Protocol)**: Routes from RIP are redistributed into EIGRP. 2. **EIGRP (Enhanced Interior Gateway Routing Protocol) to RIP (Routing Information Protocol)**: Routes from EIGRP are redistributed into RIP. 3. **External Routes**: Redistributed routes are marked as external. **External Routes** - **Marking**: Redistributed routes are marked as external. - **Preference**: Internal routes are preferred over external routes. **Redistribution Requirements** - **Dual Protocols**: Routers must run both protocols. - **Static/Connected Routes**: Can also be redistributed. **Routing Tables** - **Presence**: Only routes in routing tables can be redistributed. - **Next Hop**: Routes with unknown next hops cannot be redistributed. **Metrics and Autonomous System Considerations** - **Metric Compatibility**: Ensure metrics are converted appropriately. - **RIP**: Max hop count of 15. - **EIGRP**: Uses complex metrics. - **Invalid Routes**: If the metric exceeds 15 in RIP, the route is invalid. - **Autonomous System Number (ASN)**: Manage AS numbers and administrative distances during redistribution. **VLAN** ======== - **VLAN (Virtual Local Area Network)**: Allows devices to be logically grouped into separate networks, regardless of their physical location. **Key Features** - **Logical Grouping**: Devices can be part of the same VLAN even if they are physically apart. - **Traffic Isolation**: Devices in one VLAN do not see traffic from other VLANs. - **Improved Security**: Prevents sensitive data from being accessed by unauthorized departments. - **Broadcast Domain Segmentation**: Reduces broadcast traffic by dividing the network into smaller broadcast domains, improving performance. **How VLANs Work** - **Implementation**: VLANs are set up on VLAN-capable switches. - **Port Assignment**: Switch ports are assigned to specific VLANs. - **Example**: Support computers to VLAN 1, Accounting to VLAN 2, Shipping to VLAN 3. - **Traffic Isolation**: Devices from different VLANs share the same cabling and switch but their traffic remains isolated. **Benefits of VLANs** - **Traffic Management**: Reduces congestion by limiting broadcast traffic within each VLAN. - **Scalability**: Helps manage broadcast traffic as the network grows. - **Flexibility**: Allows logical grouping of devices without physical reorganization or additional hardware. **NETWORKING BASIC** ==================== **Computer Network**: A system where two or more computers are connected for communication and resource sharing. **Networking**: Involves the construction, design, and use of a network, including: - **Physical Components**: Cables, hubs, bridges, switches, routers. - **Telecommunication Protocols**: Manage and use the network. - **Software**: For network management. - **Operation Policies and Procedures**: Related to resource sharing. **Common Network Terminologies** - **Bit**: A unit of data represented as 0 or 1. - **Byte**: A group of 8 bits. - **Communication**: Transferring information from a sender to a receiver. - **Collision**: When two devices transmit data simultaneously, causing data loss. - **Connection**: The established link for data transfer. - **DHCP (Dynamic Host Configuration Protocol)**: Automatically assigns IP addresses to devices. - **Ethernet**: The most common LAN technology. - **Gateway**: Device that connects two different networks. - **MAC Address**: A unique hardware identifier for network devices. - **Internet**: The global network connecting millions of networks. - **IP Address**: A 32-bit address assigned to devices on a network. - **Packet**: A unit of data sent over a network. - **Protocol**: Rules for data transmission over a network. - **Server**: A computer providing services like data, email, and file sharing to clients. **Network Classifications** - **Local Area Networks (LANs)**: Covers a small area like a home, office, or building. - **Wide Area Networks (WANs)**: Covers a broad area, often using public communication links. - **Metropolitan Area Networks (MANs)**: Interconnects users in a city-wide area, larger than a LAN but smaller than a WAN. - **Personal Area Networks (PANs)**: For one individual, typically for wireless communication between personal devices. - **SAN (Storage Area Network)**: High-speed network providing access to **storage**. - **EPN (Enterprise Private Network)**: Private network for a business. - **VPN (Virtual Private Network)**: Securely extends a private network over the internet. **Networking Hardware** 1. **Hub**: - Operates at **Layer 1** (Physical layer). - Broadcasts data to all connected devices in a **LAN**. 2. **Modem**: - Converts **digital data** into analog signals and vice versa. - Used in **broadband** internet connections. 3. **Switch**: - Operates at **Layer 2** (Data Link layer). - Uses **MAC addresses** to forward data to the intended device. 4. **Router**: - Operates at **Layer 3** (Network layer). - Connects different networks, directing data between them using **IP addresses**. 5. **Bridge**: - Operates at **Layer 2**. - Connects network segments, filtering traffic based on **MAC addresses**. 6. **Repeater**: - Operates at **Layer 1**. - Extends the range of a network by amplifying and retransmitting signals. 7. **Access Point**: - Allows **wireless devices** to connect to a wired LAN via **Wi-Fi**. **Basic Elements of Networking** - **Network Media**: Cabling or wireless transmission used to connect devices. - **Network Interface Card (NIC)**: Hardware that connects a computer to the network. - **Network Connectivity Devices**: Hubs, switches, routers that direct network traffic. - **Networking Standards**: Ensure interoperability between hardware and protocols. - **Networking Protocols**: Rules for communication over the network. - **Network Operating System**: Software that manages network resources and services. **TOPOLOGY** ============ **Networking Topology** - The **physical** and **logical** arrangement of nodes and connections in a network. **Types of Topology:** 1. **Point-to-Point**: Direct connection between a sender and receiver. 2. **Bus Topology**: - All devices connect to a **single cable**. - Bi-directional but prone to **collisions** and **failures** if the main cable breaks. 3. **Ring Topology**: - Devices form a ring, each connected to two others. - High-speed but **one node failure** can disrupt the network. 4. **Tree Topology**: - Hierarchical structure with a **central hub**. - Allows for **easy expansion** but **central hub failure** affects the entire network. 5. **Star Topology**: - Devices connect to a **central hub**. - Easy to troubleshoot but **hub failure** collapses the network. 6. **Hybrid Topology**: - Combines multiple topologies. - Highly **flexible** but complex and **costly** to implement. 1. extensive cabling and network devices. 7. **Mesh Topology**: - Each device is connected to every other device. - Offers **high security** and **reliability** but **expensive** to set up. **OSI LAYERS** ============== - **OSI (Open Systems Interconnection):** A conceptual framework used to understand and implement network communications. 1. **Physical Layer**: Handles the **physical connection** between devices, including cables, switches, and other hardware. It transmits raw bitstreams over a physical medium. 2. **Data Link Layer**: Ensures reliable **data transfer** across the physical link. It deals with MAC addresses, error detection, and correction. 3. **Network Layer**: Manages data **routing and forwarding**. It handles logical addressing (IP addresses) and determines the best path for data to travel. 4. **Transport Layer**: Provides end-to-end communication and error recovery. It ensures complete data transfer with protocols like TCP and UDP. 5. **Session Layer**: Manages sessions or connections between applications. It establishes, maintains, and terminates connections. 6. **Presentation Layer**: Translates data between the application layer and the network. It handles data encryption, compression, and translation. 7. **Application Layer**: Interfaces directly with end-user applications. It provides network services to applications like email, file transfer, and web browsing. **CLASSFUL IP ADDRESSING** ========================== - **IPv4**: Introduced in 1983, 32-bit addresses in decimal notation. **Parts of IPv4** - **Network Part**: Identifies the network and its class. - **Host Part**: Identifies individual machines within the network. - **Subnet Number**: Optionally divides large networks into smaller subnets. **Characteristics of IPv4** - **Format**: 32-bit address, dotted decimal. - **Header**: 12 fields, 20 bits each. - **Addressing**: Unicast, broadcast, multicast. - **Protocols**: VLSM, ARP, RIP. - **Design**: Manual or DHCP. - **Fragmentation**: Packet fragmentation allowed. **Advantages of IPv4** - **Security**: Supports encryption. - **Allocation**: Significant network allocation. - **Efficiency**: No NAT needed, efficient communication. - **Scalability**: Scalable routing, efficient addressing. - **Multicast**: Specific data communication. **Limitations of IPv4** - **Address Exhaustion**: Limited space. - **Routing**: Inefficient internet routing. - **Management**: High costs, complexity. - **Security**: Optional features. - **Future Needs**: Limited support for advanced features. **Classful IP Addressing** - **Notation**: Dotted decimal, hexadecimal. - **Classes**: A, B, C, D, E. - **Class A**: Large networks. - **Class B**: Medium to large networks. - **Class C**: Small networks. - **Class D**: Multicasting. - **Class E**: Experimental. **Special IP Address Ranges** - **Link-local**: 169.254.0.0 -- 169.254.0.16. - **Loopback**: 127.0.0.0 -- 127.0.0.8. - **Reserved**: 0.0.0.0 -- 0.0.0.8. **Rules for Assigning Host IDs** - **Uniqueness**: Each host ID must be unique. - **No All-Zero Host ID**: Represents the network ID. - **No All-One Host ID**: Reserved for broadcast. - **No Start with 127**: Reserved for loopback. - **No All-One Network ID**: Reserved for broadcast. - **No All-Zero Network ID**: Denotes a specific host on the local network. **NETWORKING EQUIPMENT** ======================== 1. **Hub**: - Operates at **Layer 1** (Physical layer). - Broadcasts data to all connected devices in a **LAN**. 2. **Modem**: - Converts **digital data** into analog signals and vice versa. - Used in **broadband** internet connections. 3. **Switch**: - Operates at **Layer 2** (Data Link layer). - Uses **MAC addresses** to forward data to the intended device. 4. **Router**: - Operates at **Layer 3** (Network layer). - Connects different networks, directing data between them using **IP addresses**. 5. **Bridge**: - Operates at **Layer 2**. - Connects network segments, filtering traffic based on **MAC addresses**. 6. **Repeater**: - Operates at **Layer 1**. - Extends the range of a network by amplifying and retransmitting signals. 7. **Access Point**: - Allows **wireless devices** to connect to a wired LAN via **Wi-Fi**. 8. **Firewall**: - Provides security by filtering network traffic.