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Juniper Networks Certified Associate, Junos (JNCIA-Junos) JN0-106 · Domain 1: Networking fundamentals

ARP: resolving an IPv4 next hop to a MAC address; gratuitous ARP; `show arp`

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Last reviewed September 25, 2026 · Leer en español

IP addresses tell a device where a packet is going, but on an Ethernet link the frame still needs a destination MAC address. ARP (Address Resolution Protocol) bridges that gap for IPv4. Every time a Junos router sends a packet out an Ethernet interface to a next hop, it needs that next hop's MAC address, and ARP is how it gets it.

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