Packet Analysis, Encapsulation, and Ethernet Foundations

Apply the OSI and TCP/IP models to identify the headers present at each stage of an end-to-end flow.

Construct Wireshark capture and display filters that isolate a specified protocol exchange.

Decode the destination MAC, source MAC, EtherType, payload, optional 802.1Q tag, and FCS roles in an Ethernet II frame.

Predict a switch’s forwarding, filtering, and flooding decisions from its MAC address table.

Trace an ARP request and reply through a subnet and identify abnormal ARP behavior in a packet capture.

Interpret 802.1Q tags, VLAN IDs, trunk behavior, and native-VLAN handling in captured Ethernet frames.

Diagnose an Ethernet link problem using auto-negotiation, speed, duplex, and interface error-counter evidence.

Reconstruct the encapsulation and de-encapsulation path of a packet as it crosses switched and routed boundaries.