arp
View and manipulate the ARP cache
TLDR
SYNOPSIS
arp [-a] [-d address] [-s address hwaddr] [**-i** interface] [options_]
DESCRIPTION
arp manipulates the system's ARP (Address Resolution Protocol) cache. ARP maps IPv4 addresses to MAC (hardware) addresses on a local network segment.The ARP table is built dynamically as the system communicates, but entries can be manually added, deleted, or viewed for network troubleshooting.
PARAMETERS
-a
Display all entries in BSD style output format.-e
Display entries in default Linux style with fixed columns.-n, --numeric
Show numerical addresses instead of resolving hostnames.-d address
Delete an entry for the specified address. Requires root.-s address hwaddr_
Add a static ARP entry. Add temp to make it non-permanent.-i If, --device If
Limit display to a specific network interface.-D, --use-device
Use the hardware address of the specified interface instead of a hw_addr.-f filename, --file filename
Load address entries from a file (default: /etc/ethers).-v, --verbose
Verbose output.-H type, --hw-type type
Hardware type (ether, arcnet, pronet, ax25, netrom).
CAVEATS
The arp command is deprecated in favor of ip neigh on modern Linux. Static entries do not survive reboots by default. ARP is only used for IPv4; IPv6 uses Neighbor Discovery Protocol (NDP).
HISTORY
arp has been part of Unix networking since the early days of TCP/IP in the 1980s. On Linux, it is part of the net-tools package, which is being superseded by iproute2.
SEE ALSO
ip-neighbour(8), arping(8), arp-scan(1), ifconfig(8), ip(8)
