Configuring Additional File Transfer Functions
Configuring a Router as a Server
FC-246
Cisco IOS Configuration Fundamentals Configuration Guide, Release 12.1
Configuring a Router as a RARP Server
Reverse Address Resolution Protocol (RARP) is a protocol in the TCP/IP stack that provides a method
for finding IP addresses based on MAC (physical) addresses. This functionality is the reverse of
broadcasting Address Resolution Protocols (ARPs), through which a host can dynamically discover the
MAC-layer address corresponding to a particular IP network-layer address. RARP makes diskless
booting of various systems possible (for example, diskless workstations that do not know their IP
addresses when they boot, such as Sun workstations or PCs on networks where the client and server are
on separate subnets). RARP relies on the presence of a RARP server with cached table entries of
MAC-layer-to-IP address mappings.
You can configure a Cisco router as a RARP server. This feature enables the Cisco IOS software to
answer RARP requests.
To configure the router as a RARP server, use the following command in interface configuration mode:
Figure 16 illustrates a network configuration in which a router is configured to act as a RARP server.
Figure16 Configuring a Router as a RARP Server
Command Purpose
ip rarp-server ip-address Configures the router as a RARP server.
172.30.3.4E1
172.30.3.100
172.30.2.4
Sun server
S1495a
172.30.2.5
Mac address
0800.2002.ff5b
Sun workstation
E0
Router A