```{eval-rst}
.. meta::
   :description: The Address Resolution Protocol (ARP) resolves
                 network-layer addresses to link-layer MAC addresses.
   :keywords: arp, network, protocol, mac, address, ipv4, static
```

(routing_static_arp)=

# ARP

The {abbr}`ARP (Address Resolution Protocol)` resolves IPv4 network layer addresses
to link layer MAC addresses.
addresses. This mapping is essential for communication within the Internet
Protocol suite. ARP was standardized in 1982 by {rfc}`826` (STD 37).

:::{note}
In Internet Protocol version 6 (IPv6) networks, address resolution is
performed by the Neighbor Discovery Protocol (NDP).
:::

Use the following commands to configure or view ARP table entries.

## Configuration

```{eval-rst}
.. cfgcmd:: set protocols static arp interface <interface> address <host> mac <mac>

   **Configure a static ARP entry on the specified interface.**

   This creates a permanent mapping between an IP address and a MAC address
   on the specified interface.

   Example:

   .. code-block:: none

      set protocols static arp interface eth0 address 192.0.2.1 mac 01:23:45:67:89:01
```

## Operation

```{eval-rst}
.. opcmd:: show protocols static arp

   Show all ARP table entries across all interfaces.

   .. code-block:: none

      vyos@vyos:~$ show protocols static arp
      Address                  HWtype  HWaddress           Flags Mask     Iface
      10.1.1.1                 ether   00:53:00:de:23:2e   C              eth1
      10.1.1.100               ether   00:53:00:de:23:aa   CM             eth1
```

```{eval-rst}
.. opcmd:: show protocols static arp interface <interface>

   Show all ARP table entries for the specific interface.

   Example for ``eth1``:

   .. code-block:: none

      vyos@vyos:~$ show protocols static arp interface eth1
      Address                  HWtype  HWaddress           Flags Mask     Iface
      10.1.1.1                 ether   00:53:00:de:23:2e   C              eth1
      10.1.1.100               ether   00:53:00:de:23:aa   CM             eth1
```

[arp]: https://en.wikipedia.org/wiki/Address_Resolution_Protocol