Explore the basics of spanning tree, a layer 2 construct that prevents Ethernet LAN loops on redundant links, reduces broadcast storms, and stabilizes MAC tables.

Explore how spanning tree selects the root bridge, uses route bridges, and assigns root and designated ports with port costs based on link bandwidth to prevent loops.

Learn how spanning tree prevents loops by electing a root bridge and using root ports, designated ports, and blocked ports. Hello BPDU messages guide port states from blocking to forwarding.

Explore Cisco proprietary enhancements to spanning tree, including etherchannel, port fast, bpdu guard, and root guard, to speed convergence and secure edge ports.

Examine the default spanning tree configuration using show spanning tree to identify the root bridge, its priority and system id extension, and designated versus blocking ports on trunk links.

Identify the root bridge via spanning tree rules and verify with show commands. Assign VLANs 1 and 30 as primary, VLANs 40 and 50 as secondary.

Configure spanning tree convergence by setting 40 and 50 to primary and 130 to secondary, then verify traffic rerouting and edge port states with show spanning tree.

Demonstrates testing of STP convergence in regular spanning tree, reveals downtime during failover, and discusses tuning default timers or adopting rapid spanning tree.

Explore rapid spanning tree (rstp) and how it speeds convergence over regular spanning tree, using discarding, learning, and forwarding port states and Cisco extensions like port fast and bpdu guard.

Learners explore rapid spanning tree port roles, including root, designated, alternate, and backup ports, and how alternate and backup ports accelerate convergence for redundant networks.

Demonstrate rapid spanning tree implementation and faster convergence in a two-switch lab, showing all ports forwarding and alternate ports blocking to prevent loops.

Learn how spanning tree handles VLANs across switches, including PVST and PVST+, rapid PVST, and MST. Discover per-VLAN and per-LAN configurations, root bridge assignments, and how trunks carry VLANs.

Learn the essentials of troubleshooting networks, including official practices and methodologies with lab validation of designs and failures. Apply basic Cisco IOS troubleshooting tools to diagnose and resolve issues.

Explore two core troubleshooting methods—top-down and bottom-up—along with the divide and conquer approach, emphasizing repeatable, explainable steps for diagnosing network and application issues.

Identify normal network operation and document layout, traffic paths, routers, protocols, and ARP tables to establish a baseline, then troubleshoot the control plane and IP routing to isolate issues.

Explore first hop redundancy protocols such as haarp, vrrp, and glbp, and compare active-passive and active-active models to ensure reliable default gateway availability.

Examine how HSRP creates redundant routers as the subnet default gateway using a virtual IP and virtual MAC, with an active primary and a standby failover via gratuitous ARP.

Configure HSRP in a lab by setting a virtual IP for the standby group and verify failover between the active and standby routers. Learn basic HSRP concepts.

Configure hsrp with a standby group, adjust priority, and establish a virtual IP to designate the active gateway, then validate failover using pings and router power-off tests.

Configure GLBP to provide redundancy and load balance across gateways with unique virtual MAC addresses and an active virtual gateway replying to ARP.

Configure GLBP with Rose as the active gateway and Dave as backup, set group 1 and priorities 120 and 100, and verify load balancing and failover.

Learn to implement GLBP and verify failover by checking ARP and MAC addresses, running extended pings, and observing two active forwarders maintaining traffic in a lab.

Explore how ip routing moves packets between networks using layer 3 routers, covering connected, static, and dynamic routes, routing protocols such as eigrp, ospf, and bgp, and ip addressing.

Explain how connected and static routes provide reachability across three routers with loopback networks, and demonstrate static routing with route summarization.

Demonstrate how connected and static routes interact, showing how the source address influences ping replies and why reciprocal routes behind each router are needed for return traffic.

Explore how routing protocols let routers share known routes, advertise networks, choose the best path using metrics, and adapt to changes, covering IGPs, EGPs, OSPF, and RIP with administrative distance.

Explore distance vector routing protocols like rip v1, v2, drp, and IGMP, which advertise distance and vector with periodic updates and slow convergence.

Explore loop prevention in distance vector protocols, including route poisoning, infinity metrics (16), split horizon, triggered updates, and poisoned reverse to reduce routing loops.

Explore distance vector loop prevention in redundant networks, explaining counting to infinity, split horizon, poison reverse, and triggered updates, and how the hold-down timer in RIP mitigates routing loops.

Explore how link state routing protocols, led by OSPF, use link state advertisements and SPF (Dijkstra) to build a complete network map, flood LSAs, and achieve fast convergence.

Overview of EIGRP, a Cisco proprietary hybrid distance-vector protocol that uses hello packets to form neighbors, authenticates via AS values, and exchanges routes with a full update and partial updates.

Explore how EIGRP uses a composite metric with k values to select routes. Learn how reported distance and feasible distance determine successors and feasible successors for fast convergence.

Implement EIGRP across a five-router network, examine metrics and routing tables, and adjust bandwidth on point-to-point links to influence the data path and auto summary behavior.

Configure EIGRP across the enterprise, disable auto summary on all routers to avoid classful summarization, verify adjacencies and routes, and achieve a fully converged edge router network.

Examine the neighbor and topology tables in GAAP, noting hello timers, uptime, RTT, queue counts, and feasible distance with advertised distances and route states.

Manipulate network metrics to see how bandwidth and delay affect routing, adjusting interface bandwidths on the Jayde–Dave link to reflect a 1.5 megabit connection and observe metric changes.

Understand auto summarization: routers generate summary routes across classful boundaries, reducing routing table size and processing, with options to disable auto summary and use manual summarization.

Explore how OSPF, the open shortest path first link-state interior routing protocol, builds a network topology through neighbor discovery, LSDB exchange, and SPF route calculation.

Learn how OSPF neighbor selection works by matching subnet, hello and dead intervals, area id, and authentication, with CCNA-level troubleshooting and lab examples.

Learn how OSPF assigns router IDs, why loopback interfaces win, and how init and two-way neighbor states establish neighbor relationships before link-state database exchange.

Explains how ospf uses link state advertisements to build the link-state database and propagate topology, detailing neighbor establishment, link-state changes, and 30-minute lsas with type 1–3 lsas.

Explore how single-area and multi-area OSPF use areas to localize SPF calculations, with area zero as the backbone and area border routers connecting areas; understand internal routers and ASBRs.

Implement multi-area OSPF in a hands-on lab, validate route propagation, and explore the benefits of area zero and ABRs with DR/BDR relationships for network convergence.

Examine multi-area OSPF with area 10 and the backbone, focusing on type 3 summary LSAs, SPF behavior, and area border routers enabling inter-area routes.

Explore the point-to-point protocol (PPP) and its ability to encapsulate multiple layer 3 protocols, and examine LCP features such as authentication PAP and CHAP, error detection, multilink, and loop detection.

Discover how PPP authentication validates the remote router using PAP and CHAP, contrasting PAP's clear-text credentials with CHAP's challenge hash and encryption over dial-on-demand and dedicated links.

Configure two routers to form a PPP multilink bundle by enabling PPP encapsulation on serial interfaces, creating a multilink interface, assigning a bundle IP, and enabling PAP/CHAP authentication.

Configure and verify PPP authentication on a multilink serial connection by setting up PAP and CHAP, creating usernames and passwords on both ends, and validating connectivity.

Discover how frame relay provides a single wan connection per location and uses virtual circuits to interconnect remote sites through a provider's cloud, with access rate and cir defining traffic.

Explore frame relay basics with permanent and switched virtual circuits, non-broadcast multi-axis access networks, LMI status inquiries, and the locally significant data link connection identifier (DLC) connecting DTE and DC.

Explore IP addressing on frame relay networks and compare full mesh, partial mesh, and hybrid designs, highlighting how routing and subinterfaces support point-to-point and hub-and-spoke layouts.

Learn how inverse arp and Frame Relay create automatic layer 2 and layer 3 mappings using DLCIs. Practice manual map commands for static-like updates, with LMI keepalive context.

Configure a multi-site frame relay lab to build a full mesh network across four routers using inverse ARP and LMI, then verify connectivity with ping and trace route.

this lab shows configuring point-to-point frame relay in a hub-and-spoke network using subinterfaces, assigning IP addresses and DLCs, and bringing Dallas to Chicago and Dallas to Birmingham links up.

Configure point-to-point frame relay by setting serial encapsulation, dlci, and ip addresses on each router, then verify connectivity with show frame relay pvc, show ip route, and ping.

Learn to manually configure Frame Relay maps across three routers, using the Frame Relay map command on serial interfaces, disabling inverse arp, and applying the broadcast keyword for multicast.

Configure and verify manual frame relay maps across the HQ, west, and east routers, using dlci mappings, broadcast keywords, and split horizon adjustments to establish neighbor adjacencies and learned routes.

Discover how vpn and virtual private networks securely connect remote sites over the internet, using authentication, anti-replay, and data integrity to protect encrypted traffic.

Explore VPN encryption, comparing IPsec and SSL, and highlight session keys, pre-shared keys, ESP, and AnyConnect with adaptive security appliances.

Configure a GRE tunnel between HQ and remote routers using a tunnel interface, defining source and destination to connect two networks through the router of mystery in the GNS3 lab.

Configure a GRE tunnel (tunnel zero) between HQ and remote, bring the line protocol up, advertise networks on both sides, and verify with ping and trace route.

Explore IPv6 addressing concepts, including global, site-local, and link-local addresses, with routing prefixes and interface IDs (EUI-64), plus host addressing via DHCPv6 and SLAAC and Cisco router configuration basics.

Configure EIGRP for IPv6 across a multi-router network, including setting an autonomous system number and unique router IDs. Enable IPv6 EIGRP on all interfaces and verify neighbor adjacencies.

Implement EIGRPv6 across four routers in an IPv6 lab, establishing neighbor adjacencies via link-local multicast, validating route advertisements, topology, and equal-cost load balancing with an administrative distance of 90.

Configure OSPFv3 on IPv6 in a two-area lab with ABRs, enabling IPv6 OSPF on serial interfaces and reviewing the IPv6 OSPF database.

Configure OSPF version 3 on Sacramento and Phoenix with process id 42, set router IDs, enable IPv6 OSPF on serial and loopback interfaces, and form neighbor adjacencies in area 10.

Finish configuring area 15 in the IPv6 OSPF lab and verify that all area routes advertise correctly, while noting OSPFv3 SPF algorithm behavior and type 9 LSA benefits.