Mastering Applications, Systems & Networks Lab
Bridge the gap between applications, systems, and the network underneath them — live packet analysis, switching and ARP fundamentals, access-layer security, DNS/DHCP troubleshooting, routing and NAT, TCP/UDP connectivity, high availability, and a structured, capstone-driven troubleshooting methodology.
The launch will be soonCourse Highlights
Cross-Layer Diagnostics
Bridge applications, operating systems, and network layers with live packet dissection and structured end-to-end troubleshooting workflows.
Switching, ARP & GARP
Master MAC learning, CAM tables, VLAN trunking, ARP packet structures, Gratuitous ARP, Proxy ARP, and mitigation of ARP spoofing / MAC flooding.
Access-Layer Hardening
Configure Port Security, error-recovery mechanisms, DHCP Snooping, Dynamic ARP Inspection, and IP Source Guard to protect system boundaries.
Name Resolution & DHCP
Trace DHCP DORA processes, manage scopes and relays, troubleshoot name vs. IP resolution failures, and resolve complex addressing conflicts.
Transport & Connectivity
Correlate netstat/ss socket states with live Wireshark captures of the TCP three-way handshake, teardown behaviors, and UDP transport streams.
Capstone Troubleshooting
Execute structured top-down and bottom-up diagnostic methodologies, analyzing multi-layer failures spanning application, system, and network boundaries.
Practical Cross-Layer Troubleshooting
Designed for mid-to-senior engineers — systems, application, or network-focused — who want to sharpen how they reason about and troubleshoot problems that span all three layers.
Gain intensive, hands-on practice diagnosing the kinds of cross-layer issues that show up in real production environments, moving beyond siloed troubleshooting.
- Live Packet Analysis: Learn to read and interpret captures starting from fundamental Ethernet frames and IP packets up to complex app protocols.
- System & Network Correlation: Connect operating system socket states and host configurations directly with observed network traffic.
- Real-World Capstone Scenarios: Solve intricate multi-layer incidents combining application errors, system misconfigurations, and network faults.
Technologies Covered
- ✓ OSI & TCP/IP Models in Live Production Topologies
- ✓ Ethernet Frames, IP Packets & Wireshark Dissection
- ✓ Switch CAM Tables, VLANs & 802.1Q Trunking
- ✓ ARP, Gratuitous ARP (GARP), Proxy ARP & Mitigations
- ✓ Port Security, DHCP Snooping & Dynamic ARP Inspection
- ✓ DHCP DORA Process, Scopes, Relays & DNS Resolution
- ✓ Static Routing, Default Routes & NAT/PAT Operations
- ✓ TCP/UDP Socket States (netstat/ss) & Handshake Analysis
- ✓ High Availability, VIP Failovers & Load Balancer Health Checks
- ✓ Structured Top-Down / Bottom-Up Troubleshooting Methodologies
- ✓ Diagnostic Tooling: ping, traceroute, MTR, tcpdump & Wireshark
- ✓ Multi-Layer Capstone Incident Resolution
Modules & Topics
- Map the OSI and TCP/IP models to real devices, frames, and packets in a live topology
- Identify and configure basic parameters on switches, routers, and end hosts
- Configure static and DHCP-assigned addressing on hosts and verify reachability
- Capture and dissect an Ethernet frame and an IP packet to identify each header field
- Distinguish unicast, broadcast, and multicast traffic on a live segment
- Observe dynamic MAC address learning and aging in the switch CAM table
- Configure VLANs and 802.1Q trunking to segment application and system traffic
- Simulate MAC flooding and observe a switch fail open into hub-like broadcast behavior
- Capture and analyze a standard ARP request/reply exchange and inspect the local ARP cache
- Trigger and capture Gratuitous ARP (GARP) during device boot-up for duplicate IP detection
- Configure HSRP/VRRP failover and capture the GARP frame that updates the switch MAC table
- Configure Proxy ARP on a router and verify cross-subnet host-to-host communication
- Decode every field of an ARP packet: hardware/protocol type, opcode, sender/target addresses
- Simulate ARP spoofing and observe the resulting man-in-the-middle traffic redirection
- Configure Port Security with static, dynamic, and sticky MAC learning and violation modes
- Recover an error-disabled port manually and via errdisable auto-recovery
- Configure DHCP Snooping to build a trusted IP/MAC binding database
- Configure Dynamic ARP Inspection to drop spoofed ARP replies using the snooping database
- Configure IP Source Guard to prevent spoofed source-address traffic
- Apply access-port hardening: blackhole VLAN for unused ports and disabling dead ports
- Configure a DHCP server, scope, and relay for a routed environment
- Trace and capture the DHCP DORA process in Wireshark
- Configure basic DNS resolution and troubleshoot common application resolution failures
- Diagnose and resolve IP addressing conflicts and common DHCP misconfigurations
- Diagnose "works by IP, fails by name" and similar symptoms back to their DNS/DHCP root cause
- Configure static and default routing between systems on different subnets
- Configure NAT/PAT for outbound application traffic
- Trace and resolve a "no route to host" condition end-to-end
- Differentiate TCP and UDP behavior using live packet captures of each
- Correlate local socket state (netstat/ss) with observed network captures
- Diagnose port-in-use, connection-refused, and connection-timeout failures
- Verify the TCP three-way handshake and connection teardown in a live capture
- Configure a VIP-based failover pair and verify the GARP-driven MAC re-announcement
- Explain how load balancers use health checks to remove and re-add backend systems
- Capture and interpret a live failover event across switch, router, and application layers
- Build a structured top-down / bottom-up troubleshooting methodology
- Use ping, traceroute/tracert, and MTR to isolate reachability issues
- Use tcpdump/Wireshark to capture and correlate traffic across systems and network boundaries
- Run a capstone scenario diagnosing a multi-layer failure spanning app, system, and network
Start Your Lab Experience
Lab Hours Booking
Reserve access to a dedicated, pre-wired multi-layer troubleshooting environment and use your purchased lab hours whenever it suits you.
- Direct access via browser and internet connection
- Dedicated multi-vendor switches, routers, and application end hosts
- Full control over live packet captures, DHCP/DNS servers, and fault injection
- Zero hardware required on your side
- Schedule your lab session for any available date and time