Asad Ijaz
Lead Networking Architect and Editor at NetworkUstad. CCNP and CCNA certified, with 10+ years of experience in enterprise network design, implementation, and troubleshooting. Writes practical tutorials on routing, IPv4 management, network automation, and security fundamentals.
Server Message Block (SMB) Protocol: A Complete Guide
The Server Message Block (SMB) protocol enables hosts to share files, directories, printers, and other resources across a network as if those resources were local. It is a request-response protocol that operates at the Application layer, using TCP port 445 for direct communication. Every message in the SMB protocol follows a standard structure: a fixed-size...
Email Protocols: SMTP, POP3, and IMAP
Email is one of the primary services running on the internet. The email server stores email messages in a database, and email uses a store-and-forward method for sending and holding messages. Email clients communicate with servers running mail services to send and receive email, and the client-connected server in turn communicates with other mail servers...
Master TCP Reliability and Flow Control With our Exclusive Guide (Updated 2025)
Transmission Control Protocol (TCP) accepts data, segments it into chunks with headers, and encapsulates these into IP datagrams for peer exchange. TCP Reliability and Flow Control ensure complete, ordered delivery on Windows or Linux, critical for 2025 networks as of July 2025. TCP Reliability The TCP segments will possibly arrive at their destination out of...
Master TCP 3-Way Handshake and Boost Your Skills (Updated 2025)
The TCP 3-way handshake is also known as the TCP handshake. It contains three message handshakes or SYN, SYN-ACK, and ACK. It is the method for TCP/IP connection over an IP-based network. TCP’s 3-way handshaking is often called the SYN, SYN-ACK, ACK technique because there are three messages transmitted by TCP to negotiate and start...
TCP vs UDP: Transport Layer Protocols Explained
TCP and UDP are the two primary transport layer protocols handling data communication between hosts on an IP network. TCP is connection-oriented; UDP is connectionless. That single distinction cascades into almost every other difference between them — reliability, ordering, flow control, and overhead all follow from that one design choice. TCP: Connection-Oriented and Reliable Transmission...
The Transport Layer Explained: Process-to-Process Delivery, TCP, UDP, and Beyond
We routinely run multiple applications on a single device at once — a browser, an email client, a video call — and each needs its data delivered to the right place without interference from the others. The transport layer, Layer 4 of the OSI model, is what makes this possible: it accepts data from the...
IPv6 Subnetting Simplified: Unlock the Power of Next-Gen Networking
The shift to IPv6 addresses the exhaustion of IPv4’s 32-bit space, with adoption accelerating in 2025 to support IoT and global connectivity, necessitating new subnetting strategies. IPv6 addresses are increasingly replacing IPv4 due to address exhaustion, with adoption surpassing 40% globally by 2025, driving new subnetting needs. We use CIDR, VLSM, and NAT to save...
Subnetting Example with a /16 prefix – Exclusive How To Guide
In many situations, we require a large number of subnets. For example, the class B network address 130.20.0.0 has a default mask of 255.255.0.0 or /16 Prefix. So, this address has 16 network bits in the network portion and 16 host bits in the host portion. The 16 bits in the host portion are available...
Classful vs Classless Addressing Definitive Guide 2025 – From Confusion to Confidence in IP Addressing
Classful addressing emerged in the early Internet (1980s) with fixed Class A, B, and C ranges, leading to IP address exhaustion. The introduction of CIDR in 1993 marked the shift to classless addressing, allowing flexible prefixes (e.g., /20) and supporting the IPv4-to-IPv6 transition Classful and Classless addressing are terms describing IP address structure, with classless...
Subnetting Unveiled: Master the Art of Network Segmentation 2025
Subnetting allows a network administrator to create a smaller network known as sub-networks or subnets inside a large network by borrowing bits from the Host ID portion of the address. It implements and manages a practical IP addressing plan by partitioning a single physical network into more than one smaller logical sub-network (subnets), enhancing control...