Packet tracing ¶

Packet tracing is a technique to find the number of hosts between us and our target. Sometimes, we may even get information about intermediate hosts 🗺️.

The main technique used is an increasing TTL (Time-To-Live). The TTL determines the number of hops before the packet is destroyed. Intermediate machines that destroy a packet may answer back saying that the packet was destroyed.

We keep sending a packet, and increasing by one the TTL. This is how we may map the network.

Refer to the traceroute/tracepath commands, or tracert on Windows.

Additional notes

💥 Routes taken by packets may change.

📚 Some well-known operating systems have well-known TTL values. We may use that to identify the operating system that responded, while it's very unreliable.