Networking, DNS & Domains
11 Digital UtilitiesIPv4/IPv6 subnet calculators, CIDR ranges, SPF/DMARC validators, DNS records, and email deliverability. Private, secure processing with zero permanent file storage.
Networking, DNS & Domains
Network engineering and sysadmin tools. Calculate IPv4 and IPv6 subnets, validate SPF and DMARC email records, and inspect network address ranges.
IPv4 Subnet & CIDR Prefix Calculator
ip-addressingCalculate network address, broadcast address, netmask, wildcard mask, and usable host ranges for CIDR /1 to /32.
IPv6 Subnet Calculator & Full 32-Hex Expander
ipv6Expand compressed IPv6 addresses and calculate CIDR network prefixes and host capacity.
IPv4 Subnet Mask & Wildcard Mask Calculator
ip-routingCalculate network address, broadcast IP, usable host ranges, CIDR prefix, and Cisco wildcard masks.
CIDR Subnet Calculator & IPv4 Address Range Generator
ipCalculate network address, broadcast address, netmask, wildcard mask, first/last usable host, and total usable hosts from CIDR.
IPv6 Address Expander & RFC 5952 Compressor
ipExpand compressed IPv6 addresses into full 32-hex-digit 8-hextet format or compress full IPv6 using RFC 5952 canonical rules.
SPF & DMARC DNS Record Validator
email-dnsValidate and analyze DNS SPF and DMARC TXT records for syntax validity, DNS lookup counts, and email deliverability.
DNS Record Lookup & Master Zone Simulator (A, AAAA, MX, TXT)
dnsGenerate and inspect standard RFC DNS zone records and CLI dig query commands.
Email Deliverability & Disposable Domain Checker
emailValidate email syntax, detect disposable temporary domains, and flag generic role accounts.
SPF & DMARC DNS Record Generator
email-authGenerate standards-compliant TXT records for SPF email authorization and DMARC anti-spoofing policies.
Bandwidth Download & Upload Duration Calculator
bandwidthCalculate estimated download and upload durations for files across internet connection speeds with TCP/IP overhead.
Common Network Port Lookup & TCP/UDP Directory
portsSearchable directory of standard IANA and well-known TCP/UDP network ports, protocols, and service descriptions.
Frequently Asked Questions
How does the IPv4 Subnet tool display host ranges?
It calculates the network ID, broadcast address, first usable host, last usable host, and total available addresses for any CIDR mask.
Why is SPF and DMARC validation important?
Proper SPF and DMARC records prevent unauthorized spoofing of your company domain and guarantee inbox deliverability.
Does the IPv6 tool expand shortened addresses?
Yes. It expands compressed IPv6 notation into full 8-group 32-hexadecimal notation.