Every piece of data your computer sends is chopped into packets — little cars carrying a slice of cargo across the network. Watch them drive, crash, and get re-sent, then dissect them like you would in Wireshark.
ping 8.8.8.8 in the terminal at the bottom. Watch your pings literally go up in flames.tcp also matches HTTP and TLS cars — those ride inside TCP. DNS rides on UDP.
Left: the packet list — one row per car, newest at the bottom. Right: the packet details — the selected packet opened up layer by layer (Ethernet → IP → TCP/UDP/ICMP → application). Click around!
| No. | Time | Source | Destination | Proto | Len | Info |
|---|
Each protocol gets its own vehicle. The metaphors aren't just cute — they match how the protocols actually behave.
| On the highway | In real networking |
|---|---|
| 🔥 Car catches fire & veers off | Packet loss. Congested routers drop packets when their queues overflow; Wi-Fi interference and faulty cables kill them too. The packet is simply gone — nobody sends an apology note. Cause of ~every "why is it slow" ticket. |
| 🚗 New car with a RETX badge | TCP retransmission. The sender never got an ACK back, so after a timeout it sends the segment again. This is why TCP is "reliable" — and why Wireshark paints these rows black/red under Bad TCP. Watch: a burning TCP car is always followed by a RETX car. A burning UDP bike is just… gone. |
| 🚙🚙🚙 Three-sedan convoy SYN → SYN-ACK → ACK | The TCP three-way handshake. Before any real data moves, both sides agree to talk: "wanna talk?" (SYN), "sure, you?" (SYN-ACK), "yep!" (ACK). Every web page, every SSH session starts with this exact convoy. |
| 🛣️ Car stopped mid-highway, police car drives back | TTL expired (run traceroute in the terminal). Every IP packet has a Time-To-Live counter; each router decreases it by 1 and discards the packet at 0, sending back an ICMP "Time Exceeded". Traceroute maps the route by sending packets with TTL 1, 2, 3… |
tcp, dns, icmp…). In real Wireshark you'd start a capture on an interface (like eth0 or Wi-Fi), generate some traffic, then filter the noise away. Try it after playing here — it'll feel familiar.
A little terminal wired straight into the highway: every command sends real cars up there. Crank packet loss and watch ping time out while ssh shrugs it off — that's UDP/ICMP vs TCP in one experiment.