ARP Cache
The ARP cache contains entries that map IP addresses to MAC addresses.
Entries to the Address Resolution Protocol (ARP)
cache are added in one of the following ways:
- From devices that are directly attached
to the Layer 3 device.
- From an interface-based static IP route
that goes to a destination two or more router hops away. The MAC address is
either of the destination device of the router interface answering an ARP
request on behalf of the device, using proxy ARP.
The ARP cache can contain both dynamic (learned) entries and static (user-configured) entries. The software places an entry in the ARP cache:
- Dynamic—When the Layer 3 device learns a
device MAC address from an ARP request or ARP reply from the device.
- Static—When the interface with proper IP
address comes up.
For more information about ARP, see ARP Overview.
