Linux command-ARP: ARP cache for the operating system

The ARP command can view the ARP cache or manually add and remove entries from the cache.

Command format

ARP [-EVN] [-H type] [-I. If]-a [hostname]

ARP [-v] [-i if]-d hostname [PUB]

ARP [-v] [-H type] [-i if]-s hostname hw_addr [temp]

ARP [-v] [-H type] [-i if]-s hostname hw_addr [netmask NM] Pub

ARP [-v] [-H type] [-i if]-ds hostname IFA [netmask NM] Pub

ARP [-VND] [-H type] [-I. If]-f [filename]

Command parameters

-V,--verbose
Output detailed information.

-N,--numeric
Displays the address in digital form.

-H type,--hw-type type,-t type
Specifies what type of ARP entry to check, the default type is ether, the other values are Arcnet (arcnet), Pronet (pronet), ax25ax.25, Netrom (Net/rom), and so on.

-A [hostname],--all [hostname]
Displays the ARP entries for a specific host and displays all entries if no host is specified. The entries will be displayed in BSD style.

-d hostname,--delete hostname
Deletes the ARP entry corresponding to the specified host.

-E
Displays the ARP entry in the default style.

-I if,--device if
Specifies a network interface, such as eth0.

-S hostname hw_addr,--set hostname
Set the ARP entry manually.

-f filename,--file filename
Similar to the-s option, only the address information is taken from the specified file, and if no file is specified,/etc/ethers as the specified file. The contents of each line of the file are physical addresses and host names separated by spaces.

Instance

A) View the ARP cache.

[Email protected] ~]$ arpaddress                  hwtype  hwaddress           Flags Mask            Iface10.1.241.254             ether   C0 : 67:af:45:9d:3f   C                     eth010.1.241.145             ether   fa:1a:3e:b3:17:62   c                     eth010.1.241.253             Ether   00:1c:54:ff:08:13   C                     eth0

b) only display the ARP cache for eth0.

[Email protected] ~]$ arp-i eth0address                  hwtype  hwaddress           Flags Mask            Iface10.1.241.254             ether   c0:67:af:45:9d:3f   C                     eth010.1.241.145             ether   fa:1a:3e:b3:17:62   c                     eth0

c) Manual ARP entry, bind 10.1.241.253 with 00:1c:54:ff:08:13.

[Email protected] ~]$ arp-s 10.1.241.253 00:1c:54:ff:08:13

d) Delete the ARP entry corresponding to the 10.1.241.253 host.

[Email protected] ~]$ arp-d 10.1.241.253

Linux command-ARP: ARP cache for the operating system