How to check ARP table in Linux

To view the ARP table on a Linux system, you can use the arp command:

# arp -n

# arp -a

The above commands will display a list of IP addresses and their corresponding MAC addresses, along with other details like interface and flags.

To delete a specific entry from the ARP table, you can use the arp command with the -d option:

# arp -d <IP_address>

For example:

# arp -d 192.168.1.100

Note:

• The arp command is a traditional way to manage ARP tables.
• In modern Linux systems, the ip command is often preferred for more advanced network operations, including ARP table management.
• To use the ip command to view the ARP table, you can use:

# ip neigh show

To delete an entry using ip, you can use:

# ip neigh del <IP_address> dev <interface>

Replace <IP_address> with the IP address and <interface> with the interface name.

Additional Tips:

• The ARP table is automatically updated as devices are added or removed from the network.
• Entries in the ARP table are typically temporary and can be removed after a certain period of inactivity.
• You can use the -s option with the arp command to add a static ARP entry, which will persist even after a reboot.

By understanding these commands and techniques, you can effectively manage the ARP table on your Linux system.