Tools & Commands · Linux and Windows Commands
arp command
Addressing · Intermediate
Displays or edits the local cache that maps protocol addresses to hardware addresses. Viewing the cache is a normal troubleshooting step on a network you administer.
Before a host can build a local frame, it remembers which hardware address belongs to the next protocol address. This command shows that memory.
Example: arp -a prints the current cache, including the gateway's protocol address and hardware address.
Command
Platform: Windows, Linux, and macOS
arp -a
Each row pairs a protocol address with a hardware address on a local interface. Dynamic entries were learned. A missing gateway entry can explain a sudden local failure.
Common misconception
- The cache is local and temporary. It is not a directory of every hardware address on the Internet.