ssh/
SSH keys, config files, and jump hosts
Log in with keys instead of passwords, turn passwords off without locking yourself out, and keep every host’s connection details in one config file.
- Articles
- 2
- Commands to copy
- 17
- Last checked
- 24 Oct 2026
Every SSH article with the versions each was checked against
Other categories
linux/ · 3 articles
Linux
Disks that fill up, jobs that run on a schedule, and the first look at a server that has slowed down. The commands are for systemd distributions: Debian 12, Ubuntu 24.04, and RHEL 9 and its rebuilds.
- The first five minutes on a slow server
- Find what’s filling a disk
- Run a job on a schedule with systemd timers
networking/ · 3 articles
Networking
Find out what’s listening on a port, test whether a port is reachable from somewhere else, and capture the packets when the answer still isn’t clear.
- Find which process is listening on a port
- Test whether a TCP port is reachable
- Capture traffic with tcpdump
dns/ · 2 articles
DNS
Query records the way a resolver does, tell an authoritative answer from a cached one, and plan a change so it takes effect when you expect it to.
All DNS articlestls/ · 2 articles
TLS and certificates
Read what a server’s certificate says, find out when it expires, and convert keys and certificates between the formats different software asks for.
All TLS and certificates articleswindows/ · 2 articles
Windows Server
Read the event log, test connections, and look up DNS from PowerShell, with commands that work on Windows Server 2019, 2022, and 2025.
All Windows Server articles