Differences
This shows you the differences between two versions of the page.
|
ep:labs:061:contents:tasks:ex3 [2026/04/06 21:47] maria.popescu2812 [03. [30p] Packets, where are you?] |
ep:labs:061:contents:tasks:ex3 [2026/04/07 02:13] (current) radu.mantu |
||
|---|---|---|---|
| Line 5: | Line 5: | ||
| [[https://github.com/cilium/pwru|pwru]] is a tool created by Cilium to help trace network packets in the kernel's network stack and debug network connectivity issues. It does this by attaching simple eBPF programs to certain function entry points. These programs can report back to a userspace process different kinds of information, including the function that was reached, the arguments that were passed, and a CPU clock timestamp. The method used for instrumenting kernel code is based on [[https://www.kernel.org/doc/html/latest/trace/kprobes.html|kprobes]]. Ask your assistant for more information. | [[https://github.com/cilium/pwru|pwru]] is a tool created by Cilium to help trace network packets in the kernel's network stack and debug network connectivity issues. It does this by attaching simple eBPF programs to certain function entry points. These programs can report back to a userspace process different kinds of information, including the function that was reached, the arguments that were passed, and a CPU clock timestamp. The method used for instrumenting kernel code is based on [[https://www.kernel.org/doc/html/latest/trace/kprobes.html|kprobes]]. Ask your assistant for more information. | ||
| - | === [10p] Task A — A packet's journey === | + | === [10p] Task A - A packet's journey === |
| **Installation — build from source** | **Installation — build from source** | ||
| Line 71: | Line 71: | ||
| - **How does it leave the machine?** Identify the function responsible for handing the packet to the network device driver. What happens after this point? | - **How does it leave the machine?** Identify the function responsible for handing the packet to the network device driver. What happens after this point? | ||
| - **What changed with the DROP rule?** Compare the two traces side by side. At which function does the path diverge? | - **What changed with the DROP rule?** Compare the two traces side by side. At which function does the path diverge? | ||
| + | |||
