Show the ARP table with ip neigh on Linux

Use iproute2's `ip neigh` — the modern replacement for the deprecated `arp` command — to inspect or flush learned LAN neighbors.

LinuxarplanneighLow risk

Run `ip neigh show` to list known MAC/IP neighbors with their REACHABLE/STALE/FAILED states, or `ip neigh flush all` to clear the table.

01Command

Command

$ ip neigh show

02What it does

The classic `arp -a` still works on some distros but is deprecated and missing from minimal installs; `ip neigh show` is its iproute2 successor and shows richer state (REACHABLE, STALE, INCOMPLETE, FAILED). If a host changed NICs or IPs, a stale entry keeps traffic black-holing until it ages out — `sudo ip neigh flush all` clears it immediately. Filter to one interface with `ip neigh show dev eth0`.

03Risk

RiskLow risk

Requirementsiproute2

04Undo

Undo

$ ip neigh flush all

05Sources

ip-neighbour(8) — neighbour/arp tables management
Ubuntu manpages · technical · 2026-09-17
Evidence: Documents `ip neigh show` to display neighbor entries and `ip neigh flush` to erase them.

Last verified: 2026-09-17 · Category: Network