COMPUTER NETWORKING FOR CCNA BEGINERESS | IP ADDRESS Part-2 | LEARN NETWORKING

What is ROUTING?

Routing is the process of directing network traffic from one network to another. It involves determining the optimal path for data packets to reach their intended destination across an interconnected network infrastructure. Routers, specifically network devices specifically designed for routing, play a crucial role in this process.

Here's an overview of how routing works:

1. Packet forwarding: 

A device divides the data into smaller units known as packets when it wishes to transfer it to another device on a separate network. The source and destination IP addresses are among the data that are included in each packet.

For further transmission, the device transmits the packets to its default gateway, which is normally the local router.

2. Routing Table: 

Routers keep track of a routing table that lists the available networks and the most direct routes to connect to them.

Different methods, such as manual configuration, dynamic routing protocols, or a combination of both, are used to fill the routing table.

The network prefix, the router serving as the next hop, and any associated metrics or costs are normally included in each entry of the routing table.

3. Determining the Destination Network: 

A router looks at the destination IP address when it receives a packet.

Based on the destination network, the router chooses the optimum path or next hop for the packet using the routing table.

By comparing the destination IP address with the network prefixes in the routing database, the router searches for the most precise match.

4. Forwarding the Packet:
Once the router identifies the next hop for the packet, it forwards the packet to the appropriate interface connected to the next router or the destination network.

The packet continues to traverse through intermediate routers until it reaches the final destination.

5. Dynamic Routing Protocols:
Dynamic routing protocols enable routers to exchange routing information and automatically update their routing tables.

Protocols like Routing Information Protocol (RIP), Open Shortest Path First (OSPF), and Border Gateway Protocol (BGP) facilitate the exchange of routing updates between routers.

Dynamic routing protocols allow routers to adapt to changes in network topology or link conditions, improving network resilience and efficiency.

6. Internet Backbone:
At a global scale, routers within the internet backbone infrastructure handle the routing of packets between different autonomous systems and service providers.

Border routers connect different networks and exchange routing information to enable interconnectivity across the internet. 

Effective routing is essential for achieving peak network performance because it reduces latency, increases capacity utilization, and ensures dependable data delivery. Maintaining a reliable and scalable routing system requires effective network design, proper routing setup, and constant network condition monitoring.

BROADCASTING ADDRESS:-

In computer networks, the broadcast addressing technique is used to send data to every device inside a particular network segment or subnet. Instead of sending data packets to a single device or IP address, broadcast addressing uses a unique IP address to transmit them to all devices connected to the network.

In IPv4 networks, the broadcast address is typically the highest address in the network segment. For example, if a network has the IP address range 192.168.0.0/24 (which means it has 256 addresses from 192.168.0.0 to 192.168.0.255), the broadcast address would be 192.168.0.255. When a device sends a packet to the broadcast address, all devices within that network segment receive the packet.

In IPv6 networks, the broadcast address is not used. Instead, IPv6 uses multicast addresses to achieve a similar effect. Multicast addresses allow packets to be sent to a specific group of devices within a network, rather than all devices.

Broadcast addressing can be useful in certain scenarios, such as when a device needs to send a message or request to all devices on a network segment, such as a network discovery or configuration request. However, it should be used judiciously, as broadcasting can generate significant network traffic and consume bandwidth.

MULTICAST ADDRESSING:-

Multicast addressing is a method used in computer networks to send data packets to a specific group of devices rather than all devices on a network. It is an efficient way to distribute information to a select group of recipients who have expressed interest in receiving the data.

In multicast addressing, a multicast IP address is used to identify the group of devices that should receive the multicast packets. Unlike unicast addressing, where data is sent to a single device, and broadcast addressing, where data is sent to all devices, multicast allows data to be sent to a subset of devices that have joined a particular multicast group.

Multicast addresses in IPv4 are in the range of 224.0.0.0 to 239.255.255.255. The addresses 224.0.0.1 and 224.0.0.2, which are reserved for all hosts on a local network segment and all routers on a network, respectively, fall into this range. To establish communication within a specified multicast group, applications or protocols might use certain multicast addresses.

Multicast addressing is a fundamental component of IPv6 and has a significantly bigger address space. The multicast address prefix in IPv6 is ff00::/8. Similar to IPv4, certain multicast addresses have reserved uses. For example, ff02::1 is used by all nodes on a local network segment, and ff02::2 is used by all routers on a network.

Multimedia streaming, video conferencing, software distribution, and other tasks requiring simultaneous distribution of data to numerous receivers all make use of multicast addressing. It provides a productive method of distributing material to a targeted audience while reducing network traffic.

ANYCAST ADDRESSING:-

A network addressing and routing technology called anycast addressing enables several servers or devices to share a single IP address. The same IP address is given to numerous servers that are geographically dispersed across various regions or network segments via anycast addressing. The network architecture sends packets delivered to anycast addresses to the closest (in terms of network topology) available server that shares that address.

Anycast addressing offers a method for distributing network traffic in order to achieve load balancing and high availability. The objective is to route client requests to the closest or most advantageous server based on network conditions. It is frequently employed in scenarios where numerous servers or network nodes offer the same service or content.

Here's how anycast addressing works:

1. Multiple servers are assigned the same anycast IP address.

2. Each server announces anycast IP address to the network through routing protocols, such as Border Gateway Protocol (BGP).

3. The routers in the network update their routing tables to associate the anycast IP address with the closest server based on network metrics like the shortest path or lowest cost.

4. When a client sends a request to the anycast IP address, the network infrastructure routes the packet to the nearest server offering that address.

5. The server that receives the packet responds to the client's request.

Anycast addressing provides several benefits, including:

1. Improved performance: By directing traffic to the nearest server, anycast addressing reduces latency and network congestion, resulting in faster response times for clients.

2. High availability: If one server becomes unavailable, the network automatically routes traffic to the next nearest server, ensuring service continuity.

3. Load balancing: Anycast distributes traffic across multiple servers, helping to evenly distribute the workload and prevent the overloading of individual servers.

4. Scalability: Additional servers can be added to the anycast group as needed, allowing for easy scaling of services.

Anycast addressing is commonly used in content delivery networks (CDNs), Domain Name System (DNS) infrastructure, distributed databases, and other services that benefit from distributing traffic and improving performance and reliability.

GEOLOCATION:-

On the internet, geolocation is the process of figuring out a user's or a device's physical location. To pinpoint the precise location of an IP address, mobile device, or other connected device, several techniques and data sources are used.

There are different methods employed for geolocation, including:

1. IP-based geolocation: This method uses a database that maps IP addresses to geographic locations. The database is compiled by gathering information from Internet Service Providers (ISPs), Wi-Fi access points, and other sources. By comparing the IP address of a device with the entries in the database, an approximate location can be determined.

2. GPS-based geolocation: Global Positioning System (GPS) technology is used in devices equipped with GPS receivers, such as smartphones and navigation systems. GPS calculates precise location by receiving signals from satellites orbiting the Earth. This method provides highly accurate geolocation information.

3. Wi-Fi-based geolocation: Wi-Fi positioning systems use signals from nearby Wi-Fi access points to estimate the location of a device. By comparing signal strength and triangulating with known access points, an approximate location can be determined. This method is commonly used in urban areas with dense Wi-Fi coverage.

4. Cellular network-based geolocation: Mobile network providers can determine the location of a mobile device based on the cell towers it connects to. By measuring signal strength and timing, triangulation or trilateration techniques are used to estimate the device's location. This method is often used for emergency services and mobile applications.

5. Browser-based geolocation: Modern web browsers have built-in geolocation capabilities using the W3C Geolocation API. With the user's consent, the browser can access information such as Wi-Fi networks, IP addresses, and GPS data to determine the device's location.

Geolocation has various applications, including:

- Targeted advertising: Advertisers can deliver location-specific ads based on the geolocation of a user.

- Location-based services: Services such as mapping, navigation, and weather updates can tailor information based on the user's location.

- Fraud prevention: Geolocation data can be used to detect and prevent fraudulent activities, such as unauthorized access or transactions from unusual locations.

- Content localization: Websites and online services can provide localized content based on the user's location, such as language preferences and region-specific information.

It's important to note that while geolocation can provide an approximate location, it may not always be 100% accurate due to various factors like IP address allocation, network infrastructure, and privacy settings.

PUBLIC ADDRESS:-

A public address is an IP address that is globally unique and routable on the internet when referring to computer networks. It is given to systems or networks that are designed to connect to the public internet or communicate with other systems or networks there.

The Internet Protocol (IP) standards are followed when Internet Service Providers (ISPs) or regional Internet registries (RIRs) allocate public addresses. Public addresses in IPv4 are encoded as four digits separated by dots and have a 32-bit length (for example, 203.0.113.10). However, there are not enough public addresses since there are not enough IPv4 addresses accessible. Due to this shortage, IPv6, which uses 128-bit addresses and offers a far bigger pool of unique addresses, was created and adopted.

For networks or devices that must interact with other networks or services online, public addresses are crucial. Instead of using Network Address Translation (NAT) or other methods that let numerous devices use a single public address, they enable direct communication between devices.

Public addresses are used for various purposes, including:

1. Web servers: Websites hosted on servers need public addresses to be accessible to users on the internet.

2. Email servers: Public addresses are used by mail servers to send and receive emails across the internet.

3. Remote access: Devices that need to be accessed remotely, such as remote desktops or VPN servers, require public addresses.

4. Internet of Things (IoT) devices: IoT devices that connect to the Internet for monitoring, control, or data exchange typically use public addresses.

5. Peer-to-peer (P2P) networks: P2P applications and protocols require public addresses for devices to connect directly with each other.

It's worth noting that public addresses are publicly visible on the internet, which can raise security concerns. Network security devices and networks with public addresses from unauthorized access or malicious activities. measures, such as firewalls, intrusion detection systems, and access controls, are necessary to protect 

FIREWALLING:-

The act of firewalling involves putting in place network security mechanisms to guard against threats, malicious activity, and unauthorized access to computer networks. A firewall imposes security standards to regulate and track network traffic while serving as a barrier between internal network resources and external networks (usually the Internet).

In order to determine whether network packets should be allowed or banned, firewalls examine the packets and apply rules, which can be implemented as hardware or software. Here are some of the main characteristics and uses of firewalls:

1. Access Control: To decide which network traffic is allowed to enter or leave the network, firewalls utilize access control lists (ACLs) or rules. These guidelines may take into account a number of factors, including source and destination IP addresses, ports, protocols, and application-level data.

2. Packet filtering: Packet-filtering firewalls examine each packet in turn and compare it to the set of rules. Packets may be accepted, rejected, or modified depending on the regulations. Incoming HTTP (port 80) traffic, for instance, might be permitted by a firewall rule while other ports might be blocked.

3. Stateful Inspection: By monitoring the status of network connections, stateful firewalls go beyond basic packet filtering. They keep track of connections that have been made and only permit incoming packets from authentic, already-established connections. This aids in the prevention of some attacks, including spoofing and unauthorized access attempts.

4. Network Address Translation (NAT): NAT technology, which enables numerous devices on a private network to share a single public IP address, is frequently included in firewalls. In order to facilitate communication between internal and external networks, NAT changes the source and/or destination IP addresses of packets.

5. Application-Level Filtering: Also referred to as proxy-based or deep-packet inspection, certain firewalls provide application-level filtering. These firewalls examine more than just IP and port information while examining network packets. They have the ability to examine the packet payload and take actions based on the particular application or protocol being utilized. This gives you more precise control and can aid in the detection and blocking of specific sorts of malicious activity.

6. Intrusion Prevention and Detection: More sophisticated firewalls might have IPS/IDS capabilities, which allow for the prevention and detection of intrusions. These programs keep an eye out for indications of malicious behavior or well-known attack patterns in network traffic. If an attack is found, the firewall can act right away by restricting traffic or producing a warning for more investigation.

Firewalls are an essential component of network security, providing a critical layer of defense against unauthorized access and various threats. They help protect sensitive data, prevent network intrusions, and ensure the integrity and availability of network resources. It is important to regularly update firewall rules, configure them correctly, and monitor firewall logs to maintain an effective security posture.

ADDRESS TRANSLATION:-

In computer networks, address translation, more precisely Network Address Translation (NAT), is a method used to let many devices use a single public IP address. NAT allows devices on a private network to communicate with devices on the internet by translating IP addresses between the private/internal network and the public/external network.

Given the limited supply of IPv4 addresses, address translation's main goal is to preserve public IP addresses. Here is how NAT functions:

1. Private IP addresses:- are given to devices connected to a local network, such as one in a house or workplace. These IP addresses are set aside for usage only in exclusive networks and cannot be routed over the open internet. The private IP address ranges 192.168.0.0/16, 172.16.0.0/12, and 10.0.0.0/8 are frequently used.

2. Public IP Address: The ISP assigns a public IP address to the network where private devices connect to the internet. This public IP address is used to connect to other networks and is routable on the internet.

3. Translation Process: The NAT device (usually a router or firewall) adjusts the IP address information in the network packets when a device on the private network wishes to interact with a device on the internet. The public IP address is used in place of the private one.

4. Port Translation (Port Address Translation, or PAT): NAT also translates ports in addition to IP addresses. It permits many devices to use the same public IP address at once by allocating a different port number to each private device's communication session. The NAT device keeps track of the translated IP addresses and port numbers in a translation table.

5. Response Translation: When a response is received from the external network, the NAT device checks its translation table to determine which private device the response is intended for. It then reverses the translation process and forwards the response to the appropriate private IP address.

NAT offers the following advantages:

1. IP address conservation: By employing private IP addresses internally, businesses can communicate with the internet using a single public IP address, which lowers the demand for public addresses.

2. Security: By masking internal IP addresses, NAT functions as a firewall, making it more difficult for unauthorized users to get direct access to equipment on the internal network.

3. Connectivity: NAT enables private IP address-based devices to connect to the internet and exchange data with other computers, servers, or gadgets.

4. Port Multiplexing: By allocating distinct port numbers to each device on the private network, port translation allows several devices to share the same public IP address.

While NAT helps overcome the limited availability of public IP addresses, it can sometimes introduce challenges in certain network configurations, such as difficulty establishing direct connections to devices behind NAT or complications with certain network protocols like IPsec or some peer-to-peer applications. IPv6, which provides a larger address space, reduces the need for NAT by allowing devices to have globally unique addresses.