> For the complete documentation index, see [llms.txt](https://documentation.hak5.org/shark-jack-display/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://documentation.hak5.org/shark-jack-display/sharklink.md).

# SharkLink

SharkLink is a built-in tool that lets you quickly test if two Shark Jack Display devices can talk to each other across a network.

Run SharkLink by navigating to **Tools** > **SharkLink**. This tool is handy for physically verifying that your network switches, firewall rules, and VLANs are actually configured correctly and letting traffic through (or not!).

### How it works

When you start the tool, the devices use a simple two-step handshake to verify the connection:

**Discovery**: Both devices blast out a broadcast message across the network looking for each other. To make sure they only talk to your approved device, they check for a matching 4-digit code.

**Direct Test**: Once they find each other, they stop shouting and try to send a direct, one-on-one message to each other's specific IP addresses to make sure the path is completely clear.

### Configuration

SharkLink looks at a couple of basic settings saved on your device. You can change these in the Configure menu and choose to save them as your new defaults:

* **Pairing Code**: A 4-digit number used to unlock the connection (the factory default is 1337). Both Shark Jacks must be set to the exact same code, or they will ignore each other.
* **Port**: The specific port the devices use to listen for and send messages.

### Deployment

When you open SharkLink on your device, you’ll see two main options:

* **Launch SharkLink**: Starts the live search and connection test.
* **Configure**: Opens a setup wizard so you can change pairing code and port.

#### **1. Sync your Settings**

Before plugging anything in, open **Tools** > **SharkLink** > **Configure** on both devices. Make sure they are using the exact same Pairing Code and Port.

#### **2. Plug Both In**

Connect each Shark Jack Display to the two network jacks, wall ports, or switch ports you're testing.

#### **3. Start the Link**

Select **Launch SharkLink** on both screens.

* The devices will automatically wait until they detect an active ethernet connection and grab an IP address from the network.
* Once they are ready, both screens will show a "Searching..." spinner as they look for each other.

As soon as one device hears the other's broadcast, its screen will flash `DISCOVERED` and display the other device's network IP address. From here you will have the option to `[Test]` or `[Quit]`.

If the direct one-on-one messages successfully go through and bounce back, both screens will light up with Link Confirmed. You now know traffic can move freely between those two ports!

{% hint style="warning" %}
If the devices successfully find each other (Discovery) but the final test says Link FAILED, you likely have a network firewall or security rule that allows broad network searching but blocks devices from talking directly to each other.
{% endhint %}