ARP cache

Not necessary to do ARP process every time

Pair of IP address and MAC address are kept for a likke whille

When a host sends a IP packet, it looks up the ARP cache before sending ARP request

In fact, a host usualyy sends packets to same host, especially a default router.

After a little while, the pair in ARP cache will be erased.

https://scrapbox.io/files/654f908a85b760001c346b88.png