# Wireshark

Wireshark is a free and open-source packet analyzer. It is used for network troubleshooting, analysis, software and communications protocol development, and education.

## Installation

Wireshark's default interface uses Qt, the GTK+ interface is deprecated and might be removed in the future.

Install wireshark-qt or wireshark-gtk when you prefer the GTK+ interface.

Both frontends depend on the wireshark-cli package that provides the `tshark` CLI.

## Capturing as normal user

Do not run Wireshark as root, it is insecure. Wireshark has implemented privilege separation. [1]

The wireshark-cli install script sets packet capturing capabilities on the `/usr/bin/dumpcap` executable.

`/usr/bin/dumpcap` can only be executed by root and members of the `wireshark` group.

Therefore to use Wireshark as a normal user you just have to add your user to the `wireshark` group:

    sudo gpasswd -a $USER wireshark

Re-login to apply the change or use `newgrp wireshark` to open a shell with the new group and start Wireshark from there.

## A few capturing techniques

There are a number of different ways to capture exactly what you are looking for in Wireshark, by applying capture filters or display filters.

Note: To learn the capture filter syntax, see man pcap-filter(7). For display filters, see man wireshark-filter(4).

### Filtering TCP packets

If you want to see all the current TCP packets, type `tcp` into the "Filter" bar or in the CLI, enter:

    $ tshark -f "tcp"

### Filtering UDP packets

If you want to see all the current UDP packets, type `udp` into the "Filter" bar or in the CLI, enter:

    $ tshark -f "udp"

### Filter packets to a specific IP Address

- If you would like to see all the traffic going to a specific address, enter display filter `ip.dst == 1.2.3.4`, replacing `1.2.3.4` with the IP address the outgoing traffic is being sent to.

- If you would like to see all the incoming traffic for a specific address, enter display filter `ip.src == 1.2.3.4`, replacing `1.2.3.4` with the IP address the incoming traffic is being sent to.

- If you would like to see all the incoming and outgoing traffic for a specific address, enter display filter `ip.addr == 1.2.3.4`, replacing `1.2.3.4` with the relevant IP address.

Categories:

- Security
- Networking