Free tools
Free network tools, no signup
A subnet/CIDR calculator, DNS lookup & propagation checker, and IP/ASN lookup: fast and free. When you need them from real locations with live output, run a looking glass.
Subnet calculator
Network, broadcast, host range, usable hosts, netmask and wildcard for any IPv4 or IPv6 CIDR.
Open →DNS lookup
Query A, AAAA, MX, TXT, NS, CNAME and SOA records across Cloudflare and Google resolvers.
Open →IP & ASN lookup
Originating AS, network holder, announced prefix and geolocation for any IP or AS number.
Open →Need these from real locations?
Run ping, traceroute, mtr and BGP route lookups from your own servers, with live streaming output and an API. Free to start.