# ARP Command Reference ## What it does Views and manipulates the ARP cache - maps IP addresses to MAC addresses for devices on your local network. ## Basic Usage ```bash arp hostname # Show ARP entry for specific host arp -a # Show all ARP entries arp -a -n # Show all entries (numeric format) ``` ## Display Arguments | Argument | Description | |----------|-------------| | `-a` | Show all ARP entries | | `-n` | Show numeric addresses (don't resolve hostnames) | | `-l` | Use BSD-style output format | | `-i interface` | Limit to specific network interface | ## Modify ARP Table ```bash # Add static entry arp -s hostname mac_address # Delete specific entry arp -d hostname # Delete all entries arp -d -a # Load entries from file arp -f filename ``` ## Entry Options | Option | Description | |--------|-------------| | `temp` | Temporary entry (deleted on reboot) | | `pub` | Published entry (act as ARP proxy) | | `reject` | Mark as reject (drop packets) | | `blackhole` | Silently drop packets | | `ifscope interface` | Associate with specific interface | ## Quick Commands ```bash # View all known devices arp -a # Add static entry arp -s 192.168.1.100 00:11:22:33:44:55 # Remove specific device arp -d 192.168.1.100 # Clear entire ARP cache arp -d -a ``` ## Important Note > ARP shows **other devices** your computer has communicated with, not your own machine's info. Use `ifconfig` for your own network details.