3-7
Catalyst 3750 SwitchSoftware Configuration Guide
OL-8550-09
Chapter3 Assigning the Switch IP Address and Default Gateway
Assigning Switch Information
Configuring DHCP-Based Autoconfiguration
These sections contain this configuration information:
•DHCP Server Configuration Guidelines, page3-7
•Configuring the TFTP Server, page3-8
•Configuring the DNS, page3-8
•Configuring the Relay Device, page3-9
•Obtaining Configuration Files, page3-10
•Example Configuration, page3-11

DHCP Server Configuration Guidelines

Follow these guidelines if you are configuring a device as a DHCP server:
You should configure the DHCP server with reserved leases that are bound to each switch by the switch
hardware address.
If you want the switch to receive IP address information, you must configure the DHCP server with these
lease options:
•IP address of the client (required)
•Subnet mask of the client (required)
•Router IP address (default gateway address to be used by the switch) (required)
•DNS server IP address (optional)
If you want the switch to receive the configuration file from a TFTP server, you must configure the
DHCP server with these lease options:
•TFTP server name (required)
•Boot filename (the name of the configuration file that the client needs) (recommended)
•Hostname (optional)
Depending on the settings of the DHCP server, the switch can receive IP address information, the
configuration file, or both.
If you do not configure the DHCP server with the lease options described previously, it replies to client
requests with only those parameters that are configured. If the IP address and the subnet mask are not in
the reply, the switch is not configured. If the router IP address or the TFTP server name are not found,
the switch might send broadcast, instead of unicast, TFTP requests. Unavailability of other lease options
does not affect autoconfiguration.
The switch can act as a DHCP server. By default, the Cisco IOS DHCP server and relay agent features
are enabled on your switch but are not configured. These features are not operational. If your DHCP
server is a Cisco device, for additional information about configuring DHCP, see the “Configuring
DHCP” section of the “IP Addressing and Services” section of the Cisco IOS IP Configuration Guide
from the Cisco.com page under Documentation > Cisco IOS Software > 12.2 Mainline >
Configuration Guides.