Packet travel: same network
Host A (192.168.1.10) sends a web request to Host B (192.168.1.11). Both are on the same subnet, so the packet never touches a router — a switch does all the Layer 2 work. Press Play to watch the data wrap itself in layers, cross the wire, and unwrap at the far end.
— Ready when you are
Use the step tiles below or press Play to follow the packet's journey across the LAN. Each step shows what happens at that OSI layer.
What's inside the PDU right now
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What you just saw, in one paragraph
Host A encapsulated data all the way down the OSI stack: HTTP data → TCP segment → IP packet → Ethernet frame → bits. Because the destination was on the same subnet, no router was needed — ARP supplied the MAC address, and a switch forwarded the frame based purely on Layer 2 information. Host B de-encapsulated back up the stack until the web page was handed to its application.
Real Cisco commands to try
Mac Address Table
-------------------------------------------
Vlan Mac Address Port
---- ------------- ----
1 00:AA:BB:CC:DD:EE Gi0/1
1 00:1B:44:11:3A:B7 Gi0/2
Interface: 192.168.1.10
Internet Address Physical Address Type
192.168.1.11 00-1B-44-11-3A-B7 dynamic
Reply from 192.168.1.11: bytes=32 time=1ms TTL=64
Reply from 192.168.1.11: bytes=32 time=1ms TTL=64
IPv4 Address . . . : 192.168.1.10
Subnet Mask . . . . : 255.255.255.0
Default Gateway . . : 192.168.1.1
Notice the switch never looked at the IP packet inside. A switch forwards frames using MAC addresses (Layer 2) and will happily forward a packet even if the destination IP is far away — but the destination device would discard it, because it's not on that subnet. That's why destinations outside the local network must be sent to the router instead. See the Different Networks page.