Find the Subnet ID (Class B)
We are continuing our examples, doing subnetting without using any binary math. In this lesson, we are going to calculate the subnet ID, broadcast address, and the number of usable addresses given an IP address.
VPN essentials
Learn what a VPN is, why organizations rely on it, and how remote-access and site-to-site VPNs work through clear examples and easy diagrams.
Lab #3.1 - Implementing Extended Numbered ACL
Implement extended numbered ACLs on Cisco IOS-XE in a CCNA-level lab. Plan placement, write rules, verify traffic, and fix order issues with real tests.
Extended Numbered ACL
Learn how Extended Numbered ACLs work, how to configure and verify them on Cisco routers, and see practical examples for network traffic control.
Dynamic ARP Inspection (DAI)
Learn what Dynamic ARP Inspection (DAI) is, why it’s needed, how it protects the LAN from ARP spoofing, and how to configure and verify it on Cisco switches.
IEEE 802.1x
Discover why IEEE 802.1X is essential for modern network security, controlling access at the port level to stop unauthorized devices before they enter.
Switchport Port-Security
Secure your campus LAN access layer with Cisco port security. Learn how to limit MACs, block rogue devices, and recover err-disabled switchports.
DHCP Snooping
DHCP snooping protects switches from rogue DHCP servers by allowing only trusted ports to hand out IP settings and building secure IP-to-port bindings.
Key Security Concepts
Learn key network security concepts for CCNA: vulnerabilities, threats, exploits, risks, and mitigations explained with simple examples and real-world analogies.
Find the Subnet ID (Class C)
Learn how to find the subnet ID, broadcast address, and usable hosts from any IP and mask using a simple method that avoids binary math and speeds up subnetting.