Quick Reference Guide
PowerConnect B-Series TI24X Configuration Guide 611
53-1002269-02
Configuring IP parameters – Layer 3 Switches
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• If the RARP table contains an entry for the client, the Layer 3 Switch 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 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 615.
Disabling RARP
RARP is enabled by default. To disable RARP, enter the following command at the global CONFIG
level.
PowerConnect(config)# no ip rarp
Syntax: [no] ip rarp
To re-enable RARP, enter the following command.
PowerConnect(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.
PowerConnect(config)# rarp 1 1245.7654.2348 192.53.4.2