# Discovery

## Problem

I feel something tickling me, what is it?

## Solution

The description says that something is "tickling" me. It turns out that this was referring to network tickling. When I connected to the VPN, `tcpdump` showed that `10.35.2.134` is periodically pinging me.

![](/files/-MaRLM2MS3ccdfEAqhX_)

Let's open this in Wireshark to inspect the packet contents. The flag is in the ICMP data.

![](/files/-MaRLPXIzmBMW3nGMbtX)


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# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://ctf.zeyu2001.com/2021/norzhctf-2021/discovery.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.