Network & Sysadmin Tools
IPv4 subnet calculator, DNS lookup, SSL certificate monitor, HTTP headers, hash generator, and IP inspector.
All Tools in Network & Sysadmin (10)
IPv4 CIDR Subnet Calculator
Calculate network ranges, usable hosts, broadcast IP, wildcard mask, and binary notation for any CIDR.
DNS Record Lookup Tool
Inspect A, AAAA, MX, CNAME, TXT, NS, and SOA DNS records for any domain with TTL values.
SSL Certificate Checker & Expiry Monitor
Verify TLS/SSL certificate validity, expiration countdown, issuer authority, and SANs.
HTTP Response Header & Security Audit
Inspect HTTP status codes, server headers, and audit critical security headers (HSTS, CSP, XFO).
Cryptographic Hash Generator (MD5, SHA-256)
Generate cryptographic checksums and digests in MD5, SHA-1, SHA-256, SHA-512, and HMAC.
My Public IP & Geolocation Inspector
View your external public IPv4/IPv6 address, ISP hostname, country, and city coordinates.
TCP/UDP Port Number & Service Lookup
Search standard network ports (e.g. 21, 22, 80, 443, 3306, 8080) and their default protocol services.
Browser Network Latency & Ping Tester
Measure HTTP round-trip latency, jitter, and packet response times directly from your browser.
MAC Address OUI Vendor Lookup
Identify hardware manufacturer, brand, and vendor details from any network MAC address.
IPv6 Address Expander & Compressor
Expand compressed IPv6 addresses into full 32-hex notation or compress to standard notation.
Network Diagnostics & System Administration Tools
Network & Sysadmin tools provide vital diagnostic and configuration utilities for network engineers, system administrators, hosting providers, and webmasters. Effortlessly calculate IPv4 subnets, CIDR notation ranges, usable host blocks, and broadcast addresses, or run real-time DNS lookups across A, MX, NS, TXT, and CNAME records directly from our servers. Inspect SSL/TLS certificate chains, validity windows, issuer authorities, and expiration dates before outages occur, or inspect raw HTTP response headers to debug redirects, status codes, and server misconfigurations. All sysadmin tools run without third-party tracking, providing reliable insights for production maintenance.
Key Architecture & Privacy Highlights
- IPv4 subnet calculations: CIDR prefixes, wildcard masks, usable IP ranges, and broadcast IPs.
- Direct server-side DNS queries across A, AAAA, MX, NS, TXT, and CNAME records.
- SSL/TLS certificate inspection: chain validation, issuer authority, and expiration countdown.
- Raw HTTP response headers inspector and cryptographic hash calculators (MD5, SHA-256).
Frequently Asked Questions
How does the SSL certificate checker work?
It establishes a secure SSL stream connection to the target host and inspects the X.509 certificate metadata.
Does DNS lookup query my local resolver or authoritative servers?
It queries public DNS root resolvers directly via PHP dns_get_record() to return unbiased records.