Cisco 100-101 (ICND1) Exam Training Made Easy

Explore network typologies and distinguish physical versus logical topologies, including bus, ring, star, and mesh, with notes on Ethernet and frame relay for LANs and WANs.

Explore the OSI model, a seven-layer roadmap for networked systems, from physical cabling to application protocols, noting headers added at each layer and MAC addresses.

Explore how the OSI model's layer 3 addresses enable logical networks and how routers route IP traffic, then examine layer 4–7 protocols and common application protocols like HTTP and SMTP.

Explore the history and fundamentals of Ethernet, from its 1970s origins to Ethernet II and the MAC/LLC data link concepts, and compare copper twisted pair to coax variations.

Explore how Ethernet uses csma/cd to place frames on the wire, carrier sense, multiple access, and collision detect. When collisions occur, stations back off with a random delay and retry.

Explore IP concepts at layer 3, comparing TCAP and UDP, with logical IP addresses, four octets, assured delivery, congestion avoidance, and error detection, plus classless routing.

Explore switching fundamentals and layer 2 concepts, compare hubs and switches, and learn how switches use a MAC table to forward frames, reduce collisions, and segment collision and broadcast domains.

Explain how a layer 2 switch uses a MAC address table to forward frames and compare store-and-forward, cut-through, and fragment-free forwarding modes and their latency and reliability tradeoffs.

Explore how switches forward frames using store-and-forward, cut-through, and fragment-free modes, how a switch learns MAC addresses, and how it forwards frames to the correct port while reducing collisions.

Explore IP addressing basics, binary addressing, and how networks split into network and host portions, including subnet masks, /24 and /30 examples, and classless routing.

Examine ip address classes from class a to class e, using slash notations and range boundaries. Include apipa, private ranges, loopback, and multicast addresses as described.

Explore the basics of TCP/IP communications through a practical Wireshark walkthrough, covering port roles, well-known versus ephemeral ports, and the TCP three-way handshake with SYN, ACK, and FIN.

Explain how layer 3 IP addresses map to layer 2 MAC addresses using ARP, maintain ARP tables, and use broadcasts and replies to resolve addresses on Ethernet networks.

Compare TCP and UDP: TCP is connection-oriented with assured delivery and flow control, while UDP is lightweight with no guarantees, suited for real-time traffic like voice over IP and DNS.

Learn how to determine subnet masks for class A–C networks, convert decimal IPs to binary, and identify network, broadcast, and last usable host addresses using practical examples.

Determine subnet masks using binary conversion and a binary map to compute subnets and their broadcast addresses. Use cheat sheets and a JavaScript calculator, including Cisco wildcard masks, for verification.

Explore variable length subnet masks (VLSM) and how large networks use multiple masks within a classful network to conserve address space, with overlaps and summarization pitfalls.

Explore route summarization to shrink large routing tables by summarizing multiple subnets into one network, improving troubleshooting and resilience.

Master interaction with the Cisco CLI on a vanilla switch, using user exec mode, help prompts, and show commands. Practice piping output and using include, exclude, begin, and count modifiers.

Explore Cisco's command line interface basics, including privilege levels, show commands, and output redirection to flash, ftp, and tftp, with tab completion and editing shortcuts.

Guide the initial configuration dialog to set up a Cisco switch, including hostname, enable secret, enable password, VTY password, and IP on VLAN 1 for management, then save.

Learn advanced switch configuration with show and configure commands, review running config and software version, and secure access by setting a login banner and a unified VTY password.

Configure passwords on Cisco switches by using encrypted or hidden passwords, set a login banner, and secure the console and vty lines with password authentication.

Learn how to secure Cisco switch ports with port security: enable settings, apply per-interface range commands, set access mode, and configure MAC address, sticky, and maximum to control connected devices.

The lecture covers switch port security aging options (absolute and activity), configurable aging times (1–1440 minutes), violation modes (protect, restrict, shut down), and sticky MAC behavior.

Define a broadcast domain and explain how VLANs partition a switch to reduce broadcast traffic, linking VLANs to layer 2 and layer 3 concepts and IP subnets.

Configure vlans to improve security and manage traffic between dmz, internal networks, and voip; implement access versus trunk ports and vlan tagging to separate voice and data.

Spread VLANs across multiple switches using trunking to carry tagged traffic. Learn about trunk ports and the ISL and 802.1Q protocols to scale networks for security and manageability.

Compare ISL trunking and 802.1Q trunking, highlighting ISL as a legacy Cisco proprietary protocol with full-frame encapsulation, versus 802.1Q’s VLAN-tag based, cleaner frame handling.

Configure VLAN on Cisco layer 2 switches by creating a VLAN 30, naming it DMZ host, and testing with a VLAN trunk between two switches in a hands-on lab.

Configure interfaces and assign VLANs on a switch to place DMZ hosts into VLANs, and compare explicit port-based VLAN assignment with automatic VLAN creation.

Configure and verify trunking between two switches, interpret dynamic trunking negotiations, and enforce manual trunk configuration for security and consistency across VLAN 30.

Master trunking configuration between Cisco switches, including setting trunk ports, enabling auto negotiation, verifying with show interface trunk, and managing allowed VLANs for security and stability.

Explore how routers determine paths and forward packets with routing tables, using ip addresses and subnet masks, and learn about directly connected, static, dynamic routes and gateway of last resort.

Perform basic Cisco router configuration via the initial configuration dialog, set hostname, enable secret, and vty password, configure a management network, and enable ip routing.

Explore routing protocols, including how dynamic routing fills routing tables, uses default routes and gateway of last resort, replaces static routes, and achieves convergence after link failures.

Explore the two major routing protocol types—distance vector and link-state—and how they determine routes using hop count, topology-aware metrics, and convergence behavior; include hybrids like BGP.

Explore static routing and why it is evil for larger networks, using a small three-site scenario to show how manual routes and next-hop configurations require updates across multiple routers.

Explore OSPF, a widely used link-state interior routing protocol, and learn how neighbor relationships, link-state database exchange, and the Dijkstra SPF algorithm compute best paths and facilitate immediate route recalculation.

Explore how the ospf link state database builds the internal network map with lsa type 1, type 2, and type 5, and how spf updates the routing table.

Explore how OSPF selects neighbors, tune the hello and dead intervals, and verify subnet, area, authentication, and designated and backup designated router parameters to troubleshoot adjacency.

Explore how OSPF selects router IDs, why loopback interfaces win, and how neighbors progress from init to two-way before exchanging link-state databases.

Configure OSPF on the core router and advertise all interfaces and loopback networks. Validate adjacency and route propagation with show ip ospf database and show ip route.

Configure OSPF across core, east, and west routers using wildcard masks in area 0, establishing neighbor adjacencies, and advertising 172.16 and 172.26 networks while illustrating DR/BDR roles.

Explore wide area networks, carrier-grade connectivity, and the differences between dedicated and switched wan links, including t-1, ds3, metro ethernet, frame relay, isdn, and dsl.

Learn how private IP addresses are not routable on the internet and how NAT and PAT enable multiple internal hosts to share a single public IP, with practical examples.

Discover how ethernet functions as a WAN technology, with carriers provisioning ethernet connections and ethernet over MPLS linking distant sites through a layer 2 cloud.

Learn how ACLs filter traffic in Cisco IOS, inbound or outbound. Use standard ACLs (source only) and extended ACLs (source/destination and ports); note the evaluation order and the implicit deny.

Configure both a standard and an extended ACL in the lab, then apply the standard ACL outbound on the router to block a specific host and verify the result.

Apply standard access-list 15 to the outbound fast Ethernet 0/0 interface, blocking traffic to networks behind the router; verify with ping and trace route showing destination unreachable.

Configure and apply an extended ACL on the Derse router to block web traffic on port 80 from a specific host, filtering by source and destination IP and TCP port.

Apply the extended acl to the interface and validate with trace route, icmp, and web tests. Remember the implicit deny at the bottom and add necessary permits for traffic.

Explore advanced access control lists, including reflexive, dynamic, and time-based ACLs, and learn best practices for restricting telnet and ssh access via VTY lines while avoiding misconfiguration.