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PROTOCOL

✅ Application Layer Protocols (Line by Line) 1. DNS (Domain Name System) 🔹 Translates domain names (like google.com) into IP addresses. 🔸 Port: UDP 53 (and sometimes TCP 53) 2. DHCP (Dynamic Host Configuration Protocol) 🔹 Automatically assigns IP addresses to devices in a network. 🔸 Port: UDP 67 (server), UDP 68 (client) 3. FTP (File Transfer Protocol ) 🔹 Transfers files between computers (requires login). 🔸 Port: TCP 20 (data), TCP 21 (control) 4. TFTP (Trivial File Transfer Protocol) 🔹 Simplified version of FTP, no authentication, used for booting devices. 🔸 Port: UDP 69 5. SMTP (Simple Mail Transfer Protocol) 🔹 Sends emails from client to server or server to server. 🔸 Port: TCP 25 (unsecured), TCP 587 (secured), TCP 465 (SSL) 6. POP3 (Post Office Protocol version 3) 🔹 Downloads emails from server to client and deletes them from server. 🔸 Port: TCP 110 (unsecured), TCP 995 (SSL) 7. IMAP4 (Internet Message Access Protocol version 4) 🔹 Accesses and manages emails on the s...
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ACL

ACL stands for Access Control List. 👉 Definition: An ACL is a set of rules used to control which traffic is allowed or denied on a network device (like a router, switch, or firewall). In simple terms: ✅ It filters network traffic based on criteria like: IP address (who is sending or receiving the traffic) Protocol (like TCP, UDP) Port number (like HTTP port 80, FTP port 21) 🔹 Types of ACLs: 1. Standard ACL: Filters traffic only by source IP address. Simpler and used when you only care who is sending traffic. Example: Allow traffic from 192.168.1.0 network, block all else. 2. Extended ACL: Filters by source IP, destination IP, protocol type, and port numbers. More precise control. Example: Allow HTTP traffic from 192.168.1.0 to 10.0.0.5, deny everything else. 🔹 Where ACLs are used: Routers (to control incoming and outgoing traffic) Firewalls (to secure networks) Switches (to limit access to VLANs) 🔹 Why ACLs are important: ✅ Improve security by restricting unauthorized access ✅ Opti...
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TOPOLOGY

  🔗 What is Topology in Networking? Topology refers to the arrangement or layout of network devices (like computers, switches, routers) and how they are connected to each other. 🔹 Types of IP Topologies Physical Topology : Refers to the actual physical layout of devices and cables. Examples: Bus, Ring, Star, Mesh, Tree Logical (IP) Topology : Refers to how data flows logically using IP addresses regardless of physical connection. It is how the IP packets travel through the network. 📊 Types of Network Topologies Bus Topology All devices are connected to a single central cable (the "bus"). 🔹 Pros : Easy to install. 🔸 Cons : One cable failure can bring down the whole network. Star Topology All devices are connected to a central hub or switch. 🔹 Pros : Easy to manage; failure in one device doesn’t affect others. 🔸 Cons : If the hub/switch fails, the entire network goes down. Ring Topology Devices are connect...
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CCNA

  CCNA stands for Cisco Certified Network Associate . It is a certification offered by Cisco for entry-level networking professionals . This certification validates your ability to install, configure, operate, and troubleshoot medium-size routed and switched networks. ----------------------------------------------------------------------------------------------------------- 🔍 Key Details About CCNA: ✅ Full Form: Cisco Certified Network Associate 🎯 Purpose: To provide foundational knowledge in networking and make candidates job-ready for roles such as: Network Engineer Network Administrator System Administrator Technical Support Engineer 📚 What You Learn in CCNA: Networking Fundamentals IP addressing (IPv4 and IPv6) Subnetting Network protocols (TCP/IP, ICMP, ARP) Routing & Switching Static and Dynamic Routing (RIP, EIGRP, OSPF) VLANs and Inter-VLAN Routing Spanning Tree Protocol (STP) Network Access Switch configuration...
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