Disable SIP ALG on 9 Routers and Firewalls (One-Way Audio Fix)
What SIP ALG does, why it breaks modern VoIP, how to confirm it is rewriting your packets, and the exact commands to turn it off on MikroTik, Cisco IOS, Juniper SRX, FortiGate, SonicWall and Linux.
September 30, 2026
SIP Ports Firewall Rules: 4 Setups for CSF, firewalld and pfSense
Which ports a PBX really needs (SIP 5060/5061 and the RTP media range), how to open them in CSF, firewalld and pfSense, and how to restrict SIP to your trunk provider so scanners cannot brute-force extensions.
September 30, 2026
RAID Calculator
Visual RAID calculator for RAID 0, 1, 5, 6, 10, 50, 60, ZFS RAIDZ1 to RAIDZ3 and Synology SHR: mixed disk sizes, hot spares, usable space in TB and TiB, rebuild time, speed and a plain-English verdict for each level.
September 29, 2026
IP Address Converter
Convert an IPv4 address between dotted decimal, integer, hexadecimal and binary, and see its IPv4-mapped IPv6, 6to4, NAT64 and reverse-DNS forms.
September 29, 2026
Uptime SSL Blacklist Monitor: Free Email Alerts
Get free e-mail alerts when your website goes down, your SSL certificate is about to expire or your server IP or domain is listed on a major blacklist. Up to five monitors per e-mail address.
September 29, 2026
DNSSEC Checker
Check whether a domain is signed with DNSSEC: DS records at the registry, DNSKEY records in the zone, matching key tags, algorithms and live validation through Cloudflare and Google.
September 29, 2026
CSR Decoder
Decode a certificate signing request in your browser: see the subject, Subject Alternative Names, key type and size and signature algorithm before you send it to a certificate authority.
September 29, 2026
SSL Certificate Decoder
Decode a PEM SSL/TLS certificate in your browser: subject, issuer, validity dates, SAN names, key, signature algorithm, serial number and SHA-256/SHA-1 fingerprints.
September 29, 2026
Certificate Key Matcher: Free Safe Cert and Key Check
Check whether an SSL certificate, private key and CSR belong together by comparing their public keys in your browser. The private key never leaves your computer.
September 29, 2026
TCP Ping (Port 80/443 Latency)
Measure connection time to a host on port 443 or 80 with four TCP handshakes — works even where ICMP ping is blocked by firewalls.
September 29, 2026
Website Down Checker (Is It Down?)
Check whether a website is up from our server: HTTP status, redirect chain, response time, server software and security headers — a quick is-it-down-or-just-me test.
September 29, 2026
What Is My IP Address?
See your public IP address as servers see it, with reverse DNS, network owner and country — useful for firewall whitelisting in CSF, cPHulk, Imunify360 or cloud security groups.
September 29, 2026