Clear, practical guides on the standards, units and formats behind the tools — and how to use them well.
Email
DNS
Security
DMARC reports tell you who is sending email as your domain and whether it passes authentication. Here is how to read the XML and fix what it finds.
· 4 min read
DNS
Networking
Change a DNS record and it works on your phone but not your laptop. This is DNS caching, not propagation — and the TTL is the clock behind it.
· 3 min read
Email
DNS
Security
If your email lands in spam or scammers forge your domain, the fix is three DNS records working as a team. Here is what each one does.
· 4 min read
Networking
IP
Behind every IP address is a whole network with its own number — the ASN. Here is how Autonomous Systems route the internet and what they reveal.
· 3 min read
Networking
IPv6
The internet ran out of new IPv4 addresses years ago and still works thanks to clever workarounds. Here is why, and what IPv6 changes.
· 3 min read
Networking
IP
Subnetting makes people’s eyes glaze over, but the core idea is simple: split one block of IP addresses into smaller pieces. Here is how.
· 3 min read
SEO
Performance
Web
Core Web Vitals measure how a page feels — load, responsiveness and stability. One of the three changed in 2024, so here is a fresh look.
· 3 min read
SEO
Webmaster
The robots.txt file is the first thing a search engine reads on your site. Get it wrong and you can hide everything from Google. Here is how.
· 4 min read
SEO
Webmaster
A sitemap lists the pages you want crawled. It will not boost rankings, but it helps the right pages get found — and reveals hidden problems.
· 4 min read
SEO
Web
A three-digit status code tells Google how to treat each page. Getting 301 versus 302 wrong strands your ranking. Here is what matters.
· 3 min read
SEO
Webmaster
Moving a page and redirecting the old URL is healthy. The trouble starts when redirects stack into slow, wasteful chains that corrode SEO.
· 4 min read
SEO
Social
Paste a link and it blossoms into a card. That card is driven by Open Graph tags. Get them right and your links look professional everywhere.
· 4 min read
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