# T-Shark User Guide

## Installation

* See if tshark is installed.

```
tshark
apt list tshark
```

* If it is not installed.

```
sudo apt install tshark
```

* Help menu

```
tshark -h
```

## Capture Packets with Tshark

```
tshark -i wlan0 -w capture-output.pcap
```

## Reading a File

```
tshark -r [file-name.cap]
```

* When used with `wc -l` we cann see how mnay packets are in a capture

```
tshark -r [file-name.cap | wc -l]
```

## Filters

* Tshark filters are different than bpf syntax.
* If we are interested in DNS A records only we can use:

```
dns.qry.type==1
```

* Display filters are added with the `-Y` switch.
* View all DNS A records:

```
tshark -r [file-name.cap] -Y "dns.qry.type == 1"
```

* DNS requests only in a file:

```
tshark -r [file-name.pcap] -Y "dns.flags.response == 0" | wc -l
```

## Extracted data

* One way to extract data is using `-T` and `-e [field name]` switches.
* Extract the A records in the pcap, we would use `-T fields -e dns.query.name`.

```
tshark -r dns.cap -Y "dns.qry.type == 1" -T fields -e dns.qry.name
```

* An easy way to identify field names in Wireshark is to navigate to the Packet Details in the capture, highlight the interesting field, then view the bottom left corner.

## Queries

* See who queried for a particular domain:

```
tshark -r [file-name.pcap] -T fields -e ip.src 
```

* List all queries

```
tshark -r [file-name.pcap] -T fields -e ip.src 
```


---

# 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://book.ice-wzl.xyz/tool-guides/t-shark.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.