arpd

Userspace ARP cache daemon with persistent storage.

TLDR

Start ARP daemon

$ sudo arpd -a [1] -b [/var/lib/arpd/arpd.db] [eth0]

Run in foreground

$ sudo arpd -l [eth0]

SYNOPSIS

arpd [-a neighbors] [-b database] [-k] [-l] interface

arpd is a userspace ARP daemon that collects ARP information and stores it in a database. It can answer ARP requests from the kernel cache, reducing ARP traffic on large networks.
The daemon maintains a persistent ARP database that survives reboots, improving network performance and reducing broadcast traffic.

PARAMETERS

-a n

Neighbors cache size

-b file

Database file path

-k

Kernel mode (use kernel ARP cache)

-l

Don't daemonize (foreground)

-n time

Negative cache timeout

interface

Network interface to monitor

CAVEATS

Rarely needed on modern networks. May cause issues if ARP cache becomes stale. Typically only useful on very large layer 2 networks.

HISTORY

arpd is part of the iproute2 package, providing userspace ARP table management for specialized networking scenarios.