Documentation
Learn how to use each tool with step-by-step guides, examples, and best practices.
Subnet Calculator
Learn how to use the 2network IPv4 Subnet Calculator to compute network addresses, broadcast addresses, host ranges, and CIDR notation.
Read guide →Wildcard Mask Calculator
Convert between subnet masks and wildcard masks for Cisco ACL configuration. Includes ACL examples and a quick reference table.
Read guide →DNS Lookup
Perform live DNS queries using public DNS-over-HTTPS resolvers. Look up A, AAAA, MX, TXT, NS, CNAME, SOA, and other record types.
Read guide →Port Lookup
Search and explore 110+ network ports with descriptions, protocols, known vulnerabilities, Wireshark filters, and security best practices.
Read guide →IP Converter
Convert IPv4 addresses between dotted decimal, binary, hexadecimal, octal, and 32-bit integer formats instantly.
Read guide →SPF Builder
Build valid SPF TXT records for your domain with an interactive form. Supports Google, Microsoft 365, SendGrid, and 12+ email providers.
Read guide →DMARC Builder
Build a valid DMARC TXT record to protect your domain from email spoofing. Configure policy, reporting, alignment, and subdomain handling.
Read guide →VLSM Calculator
Divide a network into variable-sized subnets based on host requirements. Optimizes IP allocation with largest-first strategy.
Read guide →DKIM Generator
Generate DKIM DNS TXT records from a public key. Supports RSA and Ed25519 keys with testing mode for safe rollout.
Read guide →Reverse DNS
Generate PTR record names and reverse zone files from IPv4/IPv6 addresses, or perform live reverse lookups.
Read guide →Record Generator
Build DNS zone file entries for A, AAAA, MX, CNAME, TXT, SRV, CAA, and PTR records with correct syntax.
Read guide →IPv6 Tools
Expand, compress, and normalize IPv6 addresses. Generate EUI-64 interface identifiers from MAC addresses.
Read guide →HTTP Header Analyzer
Fetch any URL and evaluate its response headers. Grades security headers (HSTS, CSP, X-Frame-Options) with pass/fail analysis.
Read guide →TLS/SSL Checker
Check a host's TLS connection status and evaluate security header configuration with a letter grade.
Read guide →Whois Lookup
Look up domain and IP registration information using public RDAP APIs. View registrar, dates, nameservers, and network details.
Read guide →IP Geolocation
Look up the geographic location, ISP, AS number, and network details for any IP address. Includes an interactive map.
Read guide →