Cisco Catalyst 3750-X User Manual

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Catalyst 3750-X and 3560-X Switch Software Configuration Guide
OL-21521-01
Chapter 24 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.
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 in
terface-id
Configure multiple physical ports that are connected
to the D
HCP clients, and enter interface range
configuration mode.
or
Configure a single physical port that is c
onnected to
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 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.
You can enter a single VLAN ID identif
ied 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.
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.
Step 5
ip dhcp snooping information option
format remote-id [string ASCII-string |
hostname]
(Optional) Configure the remote-ID suboption.
You can configure the remote ID as:
• 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.
The default remote ID is the switch MAC address.

Cisco Catalyst 3750-X Specifications

General

Switching Capacity	160 Gbps
Stacking Bandwidth	64 Gbps
Max Stacking Units	9
Layer Support	Layer 2 and Layer 3
Form Factor	Rack-mountable
DRAM	256 MB
Flash Memory	64 MB
Model	Cisco Catalyst 3750-X Series
Ports	24 or 48 10/100/1000 Ethernet ports
Uplink Interfaces	4 SFP or 2 SFP+
Features	StackWise Plus, EnergyWise
Image	IP Base or IP Services
Operating Temperature	0 to 40°C
Operating Humidity	10 to 85% noncondensing