Logical Address

Understanding Logical Addresses: The Unsung Heroes of Network Communication

The seemingly seamless flow of data across networks relies on a complex system of addressing. While we interact with websites and servers using easily memorable domain names like google.com, the underlying communication relies on a less intuitive, yet crucial, system: logical addresses. This article will explore the concept of logical addresses, their function in network communication, different types of logical addresses, and their relationship to physical addresses. Understanding logical addresses is vital for grasping the fundamental principles of network architecture and troubleshooting network connectivity issues.

What are Logical Addresses?

Logical addresses, also known as network addresses or IP addresses (Internet Protocol addresses), are unique identifiers assigned to devices on a network. Unlike physical addresses (MAC addresses), which are hardwired into network interface cards, logical addresses are configurable and can change depending on the network configuration. They are essentially the postal codes of the internet, enabling data packets to navigate the vast expanse of interconnected networks. Instead of using physical locations, logical addresses identify devices based on their location within a network structure.

Types of Logical Addresses: IPv4 and IPv6

Currently, two major versions of logical addresses are in use: IPv4 and IPv6.

IPv4 (Internet Protocol version 4): This older addressing scheme uses a 32-bit address represented in dotted decimal notation (e.g., 192.168.1.100). Each part of the address is an 8-bit number (octet) ranging from 0 to 255. While widely used, the limited number of available addresses (approximately 4.3 billion) has led to its eventual depletion.

IPv6 (Internet Protocol version 6): Designed to address the limitations of IPv4, IPv6 employs a 128-bit address, represented using hexadecimal notation (e.g., 2001:0db8:85a3:0000:0000:8a2e:0370:7334). This significantly expands the address space, providing enough addresses for every device imaginable for the foreseeable future. IPv6 also incorporates several improvements over IPv4, including enhanced security features and simplified routing.

How Logical Addresses Work in Network Communication

When a device wants to send data to another device on a network, it uses the recipient's logical address. This address is included in the header of the data packet. Routers, the intelligent traffic controllers of the internet, use logical addresses to determine the optimal path for the packet to reach its destination. The process works as follows:

1. Source Device: The sending device encapsulates the data in a packet and adds the recipient's logical address (destination address) and its own logical address (source address) to the packet header.
2. Router: The packet travels through routers. Each router examines the destination address and uses routing tables to determine the next hop towards the destination.
3. Destination Device: Once the packet reaches the destination network, the router delivers it to the specific device using its logical address.

The Relationship Between Logical and Physical Addresses

While logical addresses guide data across networks, physical addresses (MAC addresses) are essential for communication within a local network segment. When a packet reaches its destination network, the router needs to know the physical address of the receiving device. This is achieved through a process called Address Resolution Protocol (ARP). ARP translates the logical address into the corresponding physical address, allowing the data to be delivered to the specific network interface card.

Practical Examples

IPv4 Example: Imagine you are accessing a website. Your computer might have an IPv4 address of 192.168.1.10, while the web server has an address of 172.217.160.142. Your computer sends a request to 172.217.160.142, and routers use this address to forward the request through the internet.

IPv6 Example: As IPv6 adoption grows, you might see addresses like 2001:db8:3333:4444:5555:6666:7777:8888 representing your device or a server.

Conclusion

Logical addresses are the fundamental building blocks of network communication, enabling devices to connect and exchange data across vast networks. Understanding their function, the different address types (IPv4 and IPv6), and their relationship with physical addresses is crucial for anyone involved in networking or IT. The seamless flow of information we experience daily depends heavily on this often-overlooked yet critical element of internet infrastructure.

FAQs

1. What happens if two devices have the same logical address? This is a conflict that prevents proper communication. Networks employ mechanisms like DHCP (Dynamic Host Configuration Protocol) to avoid address duplication.

2. Can I change my logical address? In most cases, your logical address is assigned dynamically by your network’s DHCP server. You can, however, configure a static IP address if needed.

3. What is the difference between a public and a private logical address? Public addresses are globally unique and routable on the internet. Private addresses are used within a private network (like a home or office network) and are not routable on the public internet.

4. How can I find my logical address? You can easily find your logical address (IP address) by searching for "IP address" in your operating system's settings.

5. Is IPv6 replacing IPv4 completely? While IPv6 is gaining traction, IPv4 is still widely used and will likely coexist with IPv6 for many years to come due to the massive existing infrastructure dependent on IPv4.

Search Results:

How does Logical Address works? - Network Engineering Stack … 16 Oct 2016 · I have some doubts over physical and logical address system. I am reading Fourouzan TCP/IP protocol suite.By reading first chapter what I understood is that to …

How are IP addresses mapped to MAC addresses? The NDP provides two message types that are of interest here: Neighbor Solicitation and Neighbor Advertisement. A node that wants to learn a link-layer address for a particular IP …

How to work out physical address corresponding to logical address? The bits for this portion of the logical address are not translated (given power of two page size). The logical (virtual) page number is number of (virtual) page counting from zero. I.e., …

When it comes to Computer Networks, what is a logical address … Let's say your computer (192.168.10.1) wants to talk to a host (10.1.1.10). In this case, 10.1.1.10 is the logical destination or address you are attempting to send traffic. Your computer however …

Determine page number and offsets for address references 215201 is logical address space provided to us which means it is a process size. 1 KB is page size which is equivalent to 2^10 or 1024 Bytes. Process divided by page size gives a quotient and …

What are logical addresses and where do they actually reside? 26 Apr 2016 · While studying about memory management, paging and segmentation there is a lot of usage of phrases like CPU generates logical addresses and logical addresses are …

Given the logical address, how to extract the page number? Logical address includes both page number and the offset within the page. Your logical address is 16 bit. Page size as mentioned is 256 = 2 8. It means that 8 bit address is necessary to …

Calculate the size of Logical and Physical Address 29 Jan 2017 · Logical address space contains 32 pages and to represent 32 pages we need 5 bits $2^5=32$. Each page contains 2048 words therefore the offset or "d" parameter can be …

computer architecture - Logical address vs physical address 19 Oct 2023 · Physical address is the precise location of data in computer memory and logical address is a virtual address that a computer program uses to access memory. While newer …

Calculate Physical Address Corresponding to Logical Addresses 2 May 2022 · Now we just need to find out the base address of the frame where page no. 1 lies and add the offset to it. From your page table, it says page no. 1 is held by frame no. 4. The …