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Cisco Catalyst Blade Switch 3130 and 3032 for Dell Software Configuration Guide
OL-13270-06
Chapter 22 Configuring DHCP Features and IP Source Guard
Configuring DHCP Server Port-Based Address Allocation
In all cases, by connecting the Ethernet cable to the same port, the same IP address is allocated through
DHCP to the attached device.
The DHCP server port-based address allocation feature is only supported on a Cisco IOS DHCP server
and not a third-party server.
Configuring DHCP Server Port-Based Address Allocation
This section contains this configuration information:
•
Default Port-Based Address Allocation Configuration, page 22-27
•
Port-Based Address Allocation Configuration Guidelines, page 22-27
•
Enabling DHCP Server Port-Based Address Allocation, page 22-27
Default Port-Based Address Allocation Configuration
By default, DHCP server port-based address allocation is disabled.
Port-Based Address Allocation Configuration Guidelines
These are the configuration guidelines for DHCP port-based address allocation:
•
Only one IP address can be assigned per port.
•
Reserved addresses (preassigned) cannot be cleared by using the
clear ip dhcp binding
global
configuration command.
•
Preassigned addresses are automatically excluded from normal dynamic IP address assignment.
Preassigned addresses cannot be used in host pools, but there can be multiple preassigned addresses
per DHCP address pool.
•
To restrict assignments from the DHCP pool to preconfigured reservations (unreserved addresses are
not offered to the client and other clients are not served by the pool), you can enter the
reserved-only
DHCP pool configuration command.
Enabling DHCP Server Port-Based Address Allocation
Beginning in privileged EXEC mode, follow these steps to globally enable port-based address allocation
and to automatically generate a subscriber identifier on an interface.
Command
Purpose
Step 1
configure terminal
Enter global configuration mode.
Step 2
ip dhcp use subscriber-id client-id
Configure the DHCP server to globally use the
subscriber identifier as the client identifier on all
incoming DHCP messages.