> ## Documentation Index
> Fetch the complete documentation index at: https://wiki.krkn.tech/llms.txt
> Use this file to discover all available pages before exploring further.

# ARP

# arp

ARP (Address Resolution Protocol) scanning for host discovery on local network segments.

***

## Usage

```text theme={null}
r4t arp <subcommand> [flags]
```

***

## Subcommands

### `arp scan`

Perform an ARP scan to discover live hosts on the local network.

```bash theme={null}
# Scan using the configured interface
r4t arp scan

# Specify an interface
r4t arp scan --interface eth0

# Print results to stdout
r4t arp scan --stdout

# Write results to file
r4t arp scan --output /tmp/arp-hosts.txt

# Retry multiple times for unreliable networks
r4t arp scan --retries 3
```

| Flag          | Short | Description                                                |
| ------------- | ----- | ---------------------------------------------------------- |
| `--retries`   | `-r`  | Number of times to retry ARP scan                          |
| `--output`    | `-o`  | Output file for results                                    |
| `--interface` | `-i`  | Network interface to use (overrides `r4t set --interface`) |
| `--stdout`    | `-s`  | Print results to stdout                                    |

ARP scanning sends raw ARP requests on the local segment and listens for replies. It only works on the directly connected network — it cannot cross routers. It is faster and more reliable than ICMP ping for host discovery on LANs.

***

## Output

Results include: IP address, MAC address, and vendor (OUI lookup). Discovered hosts can be added as targets:

```bash theme={null}
# Scan and review results
r4t arp scan --stdout

# Add discovered hosts as targets
r4t targets add 10.10.10.10
r4t targets add 10.10.10.20
```