Sarah brings the analytical edge to IGNA Online. With deep experience in Cisco networking and a sharp eye on crypto markets, she writes detailed breakdowns of BGP, VLANs, IOS variants, blockchain technology, and edge computing platforms like NVIDIA Jetson.
A practical guide to configuring TACACS+ AAA with Cisco ISE on Cisco IOS-XE. Covers per-command authorization, accounting, safe local fallback, ISE Device Admin policy sets, and SSH hardening — with real IOS-XE CLI syntax and show command output.
Master Wireshark display and capture filters for Cisco IOS-XE environments. Learn how to use Embedded Packet Capture (EPC) on your router and apply targeted filters for STP, OSPF, BGP, DHCP, DNS, TCP, QoS, and VoIP troubleshooting.
A complete guide to configuring DMVPN Phase 2 on Cisco IOS-XE, covering IKEv2 IPsec, multipoint GRE, NHRP, and the critical EIGRP commands that make spoke-to-spoke tunnels actually work.
A complete technical guide to Cisco Catalyst SD-WAN (Viptela): understand the four-component architecture (vManage, vSmart, vBond, cEdge), how OMP drives the control plane, cEdge Day-0 onboarding, Application-Aware Routing, and essential IOS-XE CLI troubleshooting commands.
A deep dive into Spanning Tree Protocol on Cisco IOS-XE: how STP and RSTP work, how to configure Root Bridge priority, PortFast, BPDUGuard, Root Guard, Loop Guard, and UDLD, and how to troubleshoot the most common STP failure scenarios in production networks.
A complete hands-on guide to configuring MPLS L3VPN on Cisco IOS-XE — VRFs, LDP, MP-BGP with VPNv4, PE-CE BGP, route distinguishers, route targets, label verification, and production troubleshooting tips with real IOS-XE CLI output.
A deep-dive guide to BGP communities — standard, extended, and large — plus prefix-lists, AS-path filters, and route-maps on Cisco IOS-XE. Includes real CLI examples, show command output, and a production checklist for network engineers.
RWA tokenization has grown from a niche experiment to a multi-hundred-billion-dollar market. Sarah Chen breaks down how tokenized Treasuries, private credit, and DeFi composability are reshaping finance — and what the real risks are.
Configure SNMPv3 with authPriv on Cisco IOS-XE, set up LibreNMS for auto-discovery, and build Grafana dashboards for interface utilization, BGP neighbor states, and CPU monitoring. Complete CLI guide with real IOS-XE show command output.
Configure centralized AAA on Cisco IOS-XE using TACACS+ and Cisco ISE, covering authentication method lists, per-command authorization, ISE policy sets, command sets, and real-world troubleshooting with full CLI examples.
A complete guide to enabling IPv6 on Cisco IOS-XE — dual-stack interfaces, OSPFv3 with address-family, DHCPv6 server and relay, RA Guard, DHCP Guard, and BGP IPv6 peering with real CLI examples.
A hands-on guide to DMVPN Phase 2 on Cisco IOS-XE — configure mGRE tunnels, NHRP, IPsec, and EIGRP for direct spoke-to-spoke VPN connectivity without static tunnel configuration between sites. Includes real CLI examples and troubleshooting guidance.
