https://nalar.dev/tags/arp/ Recent content in ARP on Nalar Hugo en-us Tue, 15 Sep 2026 00:00:00 +0700 https://nalar.dev/arp-neighbor-cache-reuses-local-ip-to-mac-mappings/ Tue, 15 Sep 2026 00:00:00 +0700 https://nalar.dev/arp-neighbor-cache-reuses-local-ip-to-mac-mappings/ <p>Sending an IPv4 packet across an Ethernet network requires two different kinds of addresses. The IP layer selects a next-hop IPv4 address, while the Ethernet frame needs a destination MAC address that identifies the next hop on the local link.</p> <p>Address Resolution Protocol (ARP) connects those two layers. A host can ask which MAC address corresponds to a local IPv4 address, receive a reply, and store the resulting mapping. Keeping that result in a neighbor cache avoids broadcasting the same question before every packet.</p>