SNMP architecture explained, then put to work: polling a real Cisco IOS XE router from Linux with both SNMPv2c and SNMPv3, including what wrong credentials look like. Covers managers, agents, OIDs, and MIBs.
Wrong device time breaks certificate validation, log correlation, and time-based auth. This article deploys NTP on real Cisco IOS XE: one router as ntp master, the others syncing to it, with genuine show output at every stage.
Static NAT, dynamic NAT, and PAT configured on a real IOS XE router in CML, with the translation table read after each one. R1 is the NAT boundary and you see exactly how each flavor rewrites addresses.
CCNA v1.1 added AI and machine learning to the blueprint. This post covers the learning types, the predictive versus generative split, real network operations use cases, and the honest limits, framed for the exam and the job.
Ansible, Puppet, Chef, and Terraform compared on the axes that separate them, then Ansible runs for real against three live Cisco IOS XE routers, including the idempotency gotcha that bites everyone the first time.
REST is how your scripts talk to a network controller. This guide covers HTTP verbs, status codes, authentication, and JSON structure, grounded in real requests against a live Cisco Modeling Labs controller.
Control plane vs data plane, northbound and southbound APIs, and the overlay, underlay, and fabric vocabulary, mapped to the Cisco products you will meet. CCNA domain 6 concepts with the routing and switching you already know kept at the center.
Harden the login prompt on Cisco IOS XE: the password-type hierarchy, minimum length enforcement, brute-force lockout, and where MFA fits, including a real brute-force attempt hitting a lab router.
Threat, vulnerability, exploit, mitigation: CCNA domain 5 hinges on keeping these terms straight. This article pins down each one, walks the attack categories the exam expects, and maps each attack to the Cisco technology that stops it.
Next-hop, exit-interface, and fully specified static routes on Cisco IOS XE, plus default, floating, and host routes. Configured in a live lab with the failure modes shown, including recursion and administrative distance gotchas.
Before administrative distance or metric ever matters, a router forwards on the most specific route containing the destination. This article proves longest prefix match on a live Cisco IOS XE router and clears up which route actually wins.
Administrative distance ranks how much a router trusts each source of routing information, and it is the reason a prefix installs via EIGRP when you expected OSPF. Here is the complete default table, the floating static design that depends on it, and a real CML capture of the same prefix...