Comprehensive references for working network engineers and CCNP/CCIE candidates. Each guide covers fundamentals, configuration, troubleshooting, and real Cisco IOS XE lab output. The kind of depth you can keep open during change windows.
Routing Protocols
How packets find their way across networks of every scale.
OSPF
Fundamentals, neighbor states, LSA types, areas, DR/BDR election, and Cisco IOS XE configuration.
Read the guide →BGP
Fundamentals, path attributes, traffic engineering, and security, with Cisco IOS XE lab output.
Read the guide →EIGRP
Fundamentals, the DUAL algorithm, K values, stub routing, and EIGRP vs OSPF on Cisco IOS XE.
Read the guide →IPv6
128-bit address format, address types, simplified header, Neighbor Discovery, SLAAC, and Cisco IOS XE configuration.
Read the guide →Switching & VLANs
Layer 2 fundamentals and the protocols that keep a campus stable.
VLANs & Layer 2 Switching
A 22-article series on VLAN fundamentals, trunking, inter-VLAN routing, EtherChannel, and troubleshooting.
Read the guide →Spanning Tree Protocol
Port roles and states, RSTP and MST, root bridge config, BPDU Guard, Root Guard, and Catalyst troubleshooting.
Read the guide →WAN & Tunneling
Wide-area technologies, from labels to overlays to tunnels.
MPLS
Labels and the label stack, LDP, L3VPN with MP-BGP and VPNv4, and segment routing.
Read the guide →SD-WAN
Architecture, MPLS comparison, Cisco Catalyst SD-WAN (Viptela), SASE convergence, and operational realities.
Read the guide →GRE Tunnels
How GRE works, packet format, Cisco IOS XE config, keepalives, MTU, and GRE over IPsec.
Read the guide →Wireless & Access Control
Who and what gets onto the network, wired and wireless.
Cisco Wireless
Catalyst 9800 configuration model, AP join, WPA3, FlexConnect, RRM, fast roaming, and SSO HA.
Read the guide →802.1X
Supplicant, authenticator, RADIUS, EAP methods, Cisco ISE, dynamic VLANs, and phased deployment.
Read the guide →Service Quality & Resilience
Keeping traffic flowing predictably and the network up.
Quality of Service
Classification, DSCP/CoS marking, MQC, LLQ, CBWFQ, policing, shaping, and QoS in SD-WAN and wireless.
Read the guide →FHRP
HSRP, VRRP, GLBP. The three protocols compared, configuration patterns, and IOS XE walkthroughs.
Read the guide →More coming
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