PacketNebula: guides for sysadmins, developers and security folksFree browser-based tools and field-tested guides for networking, cybersecurity, system administration and technical SEO. Fast answers, no fluff.https://packetnebula.com/en-usHow to see a saved WiFi password on Windowshttps://packetnebula.com/articles/see-wifi-password-windows/https://packetnebula.com/articles/see-wifi-password-windows/Forgot a WiFi password your PC already knows? One netsh wlan command shows any saved WiFi password on Windows in clear text. Steps, a real example, and the gotchas.Mon, 15 Jun 2026 00:00:00 GMTHow long does it take to crack a password in 2026?https://packetnebula.com/articles/how-long-to-crack-a-password-2026/https://packetnebula.com/articles/how-long-to-crack-a-password-2026/Real crack times for 2026: an 8 character password falls in under 2 hours offline, 16 characters holds for ages. The math, the hardware and what to do.Fri, 12 Jun 2026 00:00:00 GMTAre JWTs encrypted? No, and the difference will bite youhttps://packetnebula.com/articles/are-jwts-encrypted/https://packetnebula.com/articles/are-jwts-encrypted/JWTs are encoded and signed, not encrypted: anyone holding a token can read every claim. What the signature really protects and what never belongs in a payload.Fri, 12 Jun 2026 00:00:00 GMTSPF, DKIM and DMARC explained: the records your email needshttps://packetnebula.com/articles/spf-dkim-dmarc-explained/https://packetnebula.com/articles/spf-dkim-dmarc-explained/SPF lists who may send for your domain, DKIM signs each message, DMARC sets the policy when checks fail. How the trio works and how to deploy it safely.Fri, 12 Jun 2026 00:00:00 GMTTLS 1.2 vs TLS 1.3: what changed and what to run in 2026https://packetnebula.com/articles/tls-12-vs-tls-13/https://packetnebula.com/articles/tls-12-vs-tls-13/TLS 1.3 handshakes in one round trip instead of two, drops every broken cipher and encrypts more of the handshake. What changed, why, and how to migrate.Fri, 12 Jun 2026 00:00:00 GMTWhat is a /24? CIDR notation and subnet masks, finally clearhttps://packetnebula.com/articles/what-is-a-slash-24-subnet/https://packetnebula.com/articles/what-is-a-slash-24-subnet/A /24 is a block of 256 IPv4 addresses, 254 usable. What the slash number means, how masks work bit by bit, and how to size real networks.Fri, 12 Jun 2026 00:00:00 GMTWhat is DNS TTL? Cache, propagation and the values to usehttps://packetnebula.com/articles/what-is-dns-ttl/https://packetnebula.com/articles/what-is-dns-ttl/TTL is the number of seconds resolvers may cache a DNS answer. How it really works, why propagation is mostly waiting, and the right TTL per situation.Fri, 12 Jun 2026 00:00:00 GMT