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What vulnerability IDs and severity scores really mean, and how to prioritise patches.

45 essential terms, from zero-day to zero trust, with a quick search.

Incident first hour, common ports, Windows event IDs, Linux logs and hardening basics.

RIP, EIGRP, OSPF and IS-IS side by side: one four-router lab, configs, troubleshooting tree and exam questions.

Network engineering field guide: a three-router lab, best-path selection, troubleshooting and securing BGP.

DUAL, metrics, classic and named-mode configs, HMAC authentication and a troubleshooting decision tree.

Multi-area L1/L2 design, NET addressing, a six-router IOS XE lab, SPF, troubleshooting and authentication.

Multi-area design, LSA types, neighbor states, a five-router IOS XE lab, HMAC-SHA authentication and troubleshooting.

RIPv2 and RIPng: hop count, timers, a three-router IOS XE lab, MD5 authentication and troubleshooting.

Rapid PVST+ and MST: root bridge election, port roles, per-VLAN load balancing, BPDU/root/loop guards and troubleshooting.

802.1Q trunks, access and voice ports, SVIs and inter-VLAN routing, VTP, VLAN security and troubleshooting.

HSRP, VRRP and GLBP: virtual gateways, priority, preemption, object tracking, failover testing and hardening.

14 free tools: subnet calculators, Cisco config checker, email security checker, password tools, security self-assessment and more.

Scam quiz, red flags and a 10-minute checklist for you and your family.

In-depth special editions on the incidents shaping security right now.