Articles on monitoring, protocols, tools, home labs, uptime and the work itself. New ones arrive about once a week.
What to write down about your network, when a spreadsheet stops being enough, how to draw useful diagrams, and how to keep it all true.
Continue reading Documenting your network: diagrams, IPAM and the spreadsheet that will not die ›
Network Monitoring, Uptime & Alerting
A green ping check only proves a kernel answered. What ICMP, TCP, HTTP and synthetic checks each catch, and a layered plan for one web service.
Continue reading Ping is not monitoring: ICMP, TCP and synthetic checks compared ›
Network UPS Tools from the USB cable to a tested shutdown: drivers, upsd, upsmon, what upsc tells you, and which box should go down last.
Continue reading UPS monitoring with NUT: clean shutdowns for a home rack ›
A good runbook is the calm colleague who is awake when you are not. A six-part template, writing tips, and a full example for a core uplink.
Continue reading Runbooks an on-call engineer can use at 3 a.m. ›
Counters, five-minute graphs and red dots: how SNMP, MRTG, RRDtool, Nagios, Cacti, Zabbix, LibreNMS and Prometheus shaped the monitors we run today.
Continue reading From MRTG to Prometheus: a short history of open-source network management ›
A five-VLAN plan for a house: what goes where, which switch ports carry tags, the firewall rules between networks and how to keep casting working.
Continue reading VLANs at home: separating IoT, guests and servers ›
Four stages, the skills that move you between them, and the certifications that help. A plain plan for getting from the phone queue to the wiring closet.
Continue reading From help desk to network engineer: a realistic path ›
99.9 percent of a 30-day month is 43.2 minutes. The window, the maintenance clause and the place you measure from decide the rest.
Continue reading What 99.9 percent really allows: uptime maths and how SLAs are measured ›
Network Monitoring, SNMP & Protocols
One rsyslog server, one folder per device, logs you can grep at 2 a.m. Formats, severities, device settings, rotation and clocks for a small network.
Continue reading Syslog for small networks: collect, rotate and actually read your logs ›
SNMP & Protocols, Network Monitoring
What ifHCInOctets, ifInErrors and ifOutDiscards really count, how a rate is computed, and the worked math behind a graph that lies after a wrap.
Continue reading Interface counters explained: octets, errors, discards and the 32-bit wrap ›
Four open-source monitors, four ideas of what a measurement is. How Nagios, Zabbix, LibreNMS and Prometheus store data, where each hurts, and who each suits.
Continue reading Nagios, Zabbix, LibreNMS, Prometheus: choosing an open-source monitor ›
A page should mean someone has to act now. Symptom alerts, severity tiers, hysteresis, dependencies and three bad alerts rewritten.
Continue reading Alert fatigue: writing alerts people still read six months later ›
