Free Networking & Server Tools
Fast, private calculators for sysadmins. Everything runs in your browser, nothing is sent to a server.
IPv4 Subnet Calculator
Calculate the network, broadcast, host range, masks and more from any IPv4 address and CIDR, with a binary view and subnet splitting.
Open toolIPv6 Subnet Calculator
Expand, compress and analyze any IPv6 prefix: address range, total addresses, /64 counts, reverse DNS and prefix splitting.
Open toolMAC Address Lookup
Identify the vendor behind any MAC address or OUI prefix, with block details, randomized-MAC detection, format conversions, and bulk lookup.
Open toolLooking Glass
Run live BGP route lookups, pings and traceroutes from our own network. See how a prefix is actually routed across the internet.
Open toolRAID Calculator
Work out usable capacity, fault tolerance, efficiency and overhead for RAID 0, 1, 5, 6, and 10, with the TB vs TiB difference made explicit.
Open toolBandwidth Calculator
Convert a port speed into monthly data transfer and back (Gbps and Mbps to TB per month, with utilization) and see how 95th-percentile, metered, and unmetered billing compare.
Open toolCIDR to IP Range Converter
Expand a CIDR block into its first and last address, or collapse an arbitrary start–end IP range into the smallest set of CIDR blocks, both directions, instantly.
Open toolSPF, DKIM & DMARC Checker
Check all three email-authentication records for any domain in one click: SPF policy and lookup count, DKIM key and selector, and DMARC alignment and policy, each graded and explained.
Open toolMore tools are on the way. Have a request? Let our team know.
