Networking articles
Guides, references, and practice problems for network engineers.
subnetting
VLSM Practice Problems with Solutions — Network Design Exercises
Ten VLSM practice problems with step-by-step solutions. Practice variable length subnet masking for CCNA, CCNP, and real-world network design scenarios.
January 25, 2026
cisco
Featured
Cisco OSPF Configuration Guide — IOS Commands and Examples
Complete guide to configuring OSPF on Cisco IOS routers. Includes basic setup, multi-area OSPF, passive interfaces, redistribution, and verification commands.
January 20, 2026
subnetting
Featured
IPv4 Subnet Mask Cheat Sheet — Complete Reference
Complete IPv4 subnet mask cheat sheet with CIDR notation, usable hosts, wildcard masks, and binary representations for all prefix lengths /1 to /32.
January 15, 2026