Network engineering tools

Professional tools for network engineers

Subnet calculators, VLSM planners, Cisco script generators, and topology tools. Free, no account required, runs entirely in your browser.

127 unit tests · Open source · Zero data collection

• Subnet Calculator Compute network address, broadcast, usable host range, and wildcard mask from any CIDR block. Free →
• VLSM Planner Allocate subnets from a parent block using Variable Length Subnet Masking with utilization analysis. Free →
• Cisco IOS Scripts Generate interface configurations, OSPF, static routes, and extended ACLs ready for console paste. Free →
• IP Address Converter Convert IPv4 addresses between dotted-decimal, binary, hexadecimal, and 32-bit integer formats instantly. Free →
• Wildcard Mask Calculator Convert subnet masks to wildcard masks for Cisco ACLs and OSPF network statements. Free →
• Bandwidth Calculator Calculate effective throughput with protocol overhead and estimate file transfer times at any link speed. Free →
• CIDR Summarizer Find the smallest supernet covering a list of networks, with gap detection and Cisco summary route config. Free →
• Topology Simulator Drag-and-drop network topology builder with automatic IP assignment and adjacency tables. Beta →