Reverse Address Resolution Protocol configuration

Reverse Address Resolution Protocol (RARP) allows an IP host that does not have a means of storing its IP address across power cycles or software reloads to query a directly-attached router for an IP address. This provides a simple mechanism for directly-attached IP hosts to boot over the network.

RARP is enabled by default. However, you must create a RARP entry for each host that will use the Layer 3 device for booting. A RARP entry consists of the following information:

  • Entry sequence number in the RARP table
  • MAC address of the boot client
  • IP address the Layer 3 device assigns to the client

When a client sends a RARP broadcast to request an IP address, the Layer 3 device responds to the request by looking in the RARP table for an entry that contains the client MAC address. If the RARP table contains an entry for the client, the Layer 3 device sends a unicast response to the client that contains the IP address associated with the client MAC address in the RARP table. If the RARP table does not contain an entry for the client, the Layer 3 device silently discards the RARP request and does not reply to the client.

Parent topic: ARP - Address Resolution Protocol