Cisco Systems 3130 User Manual
21-12
Cisco Catalyst Blade Switch 3130 for Dell Software Configuration Guide
OL-13270-01
Chapter 21 Configuring DHCP Features and IP Source Guard
Configuring DHCP Features
To remove the DHCP packet forwarding address, use the no ip helper-address address interface
configuration command.
configuration command.
Enabling DHCP Snooping and Option 82
Beginning in privileged EXEC mode, follow these steps to enable DHCP snooping on the switch:
Step 6
interface range port-range
or
interface interface-id
Configure multiple physical ports that are connected
to the DHCP clients, and enter interface range
configuration mode.
to the DHCP clients, and enter interface range
configuration mode.
or
Configure a single physical port that is connected to
the DHCP client, and enter interface configuration
mode.
the DHCP client, and enter interface configuration
mode.
Step 7
switchport mode access
Define the VLAN membership mode for the port.
Step 8
switchport access vlan vlan-id
Assign the ports to the same VLAN as configured in
Step 2.
Step 2.
Step 9
end
Return to privileged EXEC mode.
Step 10
show running-config
Verify your entries.
Step 11
copy running-config startup-config
(Optional) Save your entries in the configuration file.
Command
Purpose
Command
Purpose
Step 1
configure terminal
Enter global configuration mode.
Step 2
ip dhcp snooping
Enable DHCP snooping globally.
Step 3
ip dhcp snooping vlan vlan-range
Enable DHCP snooping on a VLAN or range of VLANs. The range is 1
to 4094.
to 4094.
You can enter a single VLAN ID identified by VLAN ID number, a series
of VLAN IDs separated by commas, a range of VLAN IDs separated by
hyphens, or a range of VLAN IDs separated by entering the starting and
ending VLAN IDs separated by a space.
of VLAN IDs separated by commas, a range of VLAN IDs separated by
hyphens, or a range of VLAN IDs separated by entering the starting and
ending VLAN IDs separated by a space.
Step 4
ip dhcp snooping information option
Enable the switch to insert and remove DHCP relay information
(option-82 field) in forwarded DHCP request messages to the DHCP
server. This is the default setting.
(option-82 field) in forwarded DHCP request messages to the DHCP
server. This is the default setting.
Step 5
ip dhcp snooping information option
format remote-id [string ASCII-string |
hostname]
format remote-id [string ASCII-string |
hostname]
(Optional) Configure the remote-ID suboption.
You can configure the remote ID to be:
•
String of up to 63 ASCII characters (no spaces)
•
Configured hostname for the switch
Note
If the hostname is longer than 63 characters, it is truncated to 63
characters in the remote-ID configuration.
characters in the remote-ID configuration.
The default remote ID is the switch MAC address.