
4-7
Catalyst 3550 Multilayer Switch Software Configuration Guide
78-11194-09
Chapter 4 Assigning the Switch IP Address and Default Gateway
Assigning Switch Information
, configure the router interfaces as follows:
On interface 10.0.0.2:
router(config-if)# ip helper-address 20.0.0.2
router(config-if)# ip helper-address 20.0.0.3
router(config-if)# ip helper-address 20.0.0.4
On interface 20.0.0.1
router(config-if)# ip helper-address 10.0.0.1
Note
If the Catalyst 3550 multilayer switch is acting as the relay device, configure the interface as a routed
port. For more information, see the
“Routed Ports” section on page 10-4
and the
Interfaces” section on page 10-18
Figure 4-2
Relay Device Used in Autoconfiguration
Obtaining Configuration Files
Depending on the availability of the IP address and the configuration filename in the DHCP reserved
lease, the switch obtains its configuration information in these ways:
•
The IP address and the configuration filename is reserved for the switch and provided in the DHCP
reply (one-file read method).
The switch receives its IP address, subnet mask, TFTP server address, and the configuration
filename from the DHCP server or the DHCP server feature running on your switch. The switch
sends a unicast message to the TFTP server to retrieve the named configuration file from the base
directory of the server, and upon receipt, completes its boot-up process.
•
The IP address and the configuration filename is reserved for the switch, but the TFTP server
address is not provided in the DHCP reply (one-file read method).
The switch receives its IP address, subnet mask, and the configuration filename from the DHCP
server, or the DHCP server feature running on your switch. The switch sends a broadcast message
to a TFTP server to retrieve the named configuration file from the base directory of the server, and
upon receipt, completes its boot-up process.
•
Only the IP address is reserved for the switch and provided in the DHCP reply. The configuration
filename is not provided (two-file read method).
Switch
(DHCP client)
Cisco router
(Relay)
49068
DHCP server
TFTP server
DNS server
20.0.0.2
20.0.0.3
20.0.0.1
10.0.0.2
10.0.0.1
20.0.0.4