Networking Tools

Calculators

IPv4 Subnet CalculatorNetwork, mask, wildcard, host range and binary view for any IPv4 address.Open →Subnetting TrainerRandom subnetting questions with a score, a streak and step-by-step answers.Open →VLSM PlannerSplit one block into subnets of different sizes, largest first.Open →Wildcard Mask & ACL HelperWildcard masks and ready-to-paste ACL and OSPF/EIGRP statements.Open →IPv6 Address ToolCompress, expand and classify IPv6 addresses. EUI-64 generator.Open →Binary / Decimal / Hex ConverterDecimal, binary and hex with the working shown step by step.Open →

Cheat sheets

Ports & Protocol NumbersWell-known TCP/UDP ports and IP protocol numbers, searchable.Open →Administrative Distance TableDefault administrative distances and a "which route wins?" check.Open →Cisco IOS Command Cheat SheetCisco IOS commands by topic. Click a command to copy it.Open →

Networking tools for engineers and CCNA students

These tools cover the calculations network engineers do every day and that the CCNA exam tests again and again. The IPv4 subnet calculator shows the network and broadcast address, mask, wildcard and host range of any address. The subnetting trainer gives you random questions with step-by-step answers. The VLSM planner splits an address block into subnets of different sizes, and the wildcard mask and ACL helper builds ready-to-paste ACL and OSPF statements.

There is also an IPv6 address tool with EUI-64, a binary, decimal and hex converter, searchable tables of TCP/UDP ports and administrative distances, and a Cisco IOS command cheat sheet. Everything runs in the browser.