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How rarp differs from bootp/dhcp, Disabling rarp, Creating static rarp entries – Brocade TurboIron 24X Series Configuration Guide User Manual

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Brocade TurboIron 24X Series Configuration Guide

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Configuring IP parameters – Layer 3 Switches

If the RARP table does not contain an entry for the client, the Layer 3 Switch silently discards
the RARP request and does not reply to the client.

How RARP Differs from BootP/DHCP

RARP and BootP/DHCP are different methods for providing IP addresses to IP hosts when they
boot. These methods differ in the following ways:

Location of configured host addresses:

RARP requires static configuration of the host IP addresses on the Layer 3 Switch. The
Layer 3 Switch replies directly to a host request by sending an IP address you have
configured in the RARP table.

The Layer 3 Switch forwards BootP and DHCP requests to a third-party BootP/DHCP server
that contains the IP addresses and other host configuration information.

Connection of host to boot source (Layer 3 Switch or BootP/DHCP server):

RARP requires the IP host to be directly attached to the Layer 3 Switch.

An IP host and the BootP/DHCP server can be on different networks and on different
routers, so long as the routers are configured to forward (“help”) the host boot request to
the boot server.

You can centrally configure other host parameters on the BootP/DHCP server, in addition
to the IP address, and supply those parameters to the host along with its IP address.

To configure the Layer 3 Switch to forward BootP/DHCP requests when boot clients and the boot
servers are on different subnets on different Layer 3 Switch interfaces, refer to

“Configuring

BootP/DHCP relay parameters”

on page 483.

Disabling RARP

RARP is enabled by default. To disable RARP, enter the following command at the global CONFIG
level.

TurboIron(config)#no ip rarp

Syntax: [no] ip rarp

To re-enable RARP, enter the following command.

TurboIron(config)#ip rarp

Creating static RARP entries

You must configure the RARP entries for the RARP table. The Layer 3 Switch can send an IP
address in reply to a client RARP request only if create a RARP entry for that client.

To assign a static IP RARP entry for static routes on a router, enter a command such as the
following.

TurboIron(config)#rarp 1 0000.0054.2348 192.53.4.2

This command creates a RARP entry for a client with MAC address 0000.0054.2348. When the
Layer 3 Switch receives a RARP request from this client, the Layer 3 Switch replies to the request by
sending IP address 192.53.4.2 to the client.

Syntax: rarp .