CCNA
Cisco Certified Network Associate certification resources
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 Connection Establishment and Termination
All application processes on a server use unique port numbers. A network administrator can use default ports (e.g., 80 for HTTP, 21 for FTP) or configure custom ports manually, ensuring no conflicts. An active server application listening on an open port means the transport layer accepts and processes segments addressed to that port number. Every...
Netstat Command, Troubleshoot Connections in Seconds Exclusive 2025 Guide
Knowing which active TCP connections are open on a networked host is crucial, especially with the 2025 IoT growth. The netstat command is a vital tool for verifying these connections on Windows (e.g., 10/11) or Linux, addressing security risks from unexplained connections, a key concern as of 2025 This netstat command shows detailed information about...
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...
VLSM Insights: Avoid IP Waste with Precision Subnetting 2025 Guide
VLSM (Variable Length Subnet Masking) helps improve the use of IP address space, with applications in IPv6 internal segmentation as of June 2025. Using a variable-length subnet mask, we can assign LAN and WAN segments without wasting IP addresses. As shown in the scenario in the Figure below, the hosts in each subnetwork will be...
Master Subnetting Based on Network Requirement – Exclusive Guide 2025
Sometimes, the number of sub-networks is more critical than the number of host addresses per sub-network. For example, an organization wants to separate network traffic based on internal structure or department setup. In this case, subnetting based on network requirements is most important in determining how many bits to borrow. The addressing scheme must allow...
Master Subnetting Based on Host Requirements: Unleash Efficient Subnetting Success with Our 2025 Guide
Subnetting involves a trade-off: borrowing more host bits increases subnets but reduces hosts per subnet. For example, a /16 network with 16 host bits can be subnetted to /22 (64 subnets, 1022 hosts) or /28 (4096 subnets, 14 hosts), guiding network design as of June 2025. We consider either the host requirement or the network...