Gail is a network engineer who spent years on the night desk of ISP and campus NOCs. She writes about SNMP, polling and counters, and keeps a printed OID cheat sheet she refuses to throw away.
Count the powered ports, budget by class at the switch port, insist on SNMP if you graph things and keep it fanless. A home lab PoE switch, worked through.
Continue reading Choosing a PoE switch for a home lab: ports, power budget and SNMP ›
Netmask, wildcard, total and usable addresses for every prefix from /8 to /32, plus the block-size trick, /31 and /32 links and the private ranges.
Continue reading Subnet cheat sheet: every prefix from /8 to /32 in one table ›
SNMP & Protocols, Network Monitoring
SNMP says the link is full. Flow data says who filled it. NetFlow, IPFIX and sFlow compared, plus the sampling math that keeps you honest.
Continue reading NetFlow, sFlow and IPFIX: finding out who is using the bandwidth ›
The snmpwalk lines for v2c and v3 you will actually type, what each part of the output means, and the errors that stop a walk cold.
Continue reading snmpwalk command examples for v2c and v3, with the output explained ›
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 ›
Five minutes is a habit from the MRTG years. How to pick intervals per metric, with counter wrap math, burst examples and storage costs.
Continue reading How often should you poll? Choosing a polling interval ›
Community strings, USM users, GETBULK and 64-bit counters: what each SNMP version changed, and when v2c is still a fair choice.
Continue reading SNMP v1, v2c and v3: what changed and which one to run ›
