Cisco Catalyst 2960 Series, Configuration Manual

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Purpose Command or Action
• 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.
Enables 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. ip dhcp snooping information option
Example:
Switch(config)#
ip dhcp snooping
information option
Step 5
(Optional) Configures the remote-ID suboption. ip dhcp snooping information option format
remote-id
[ string ASCII-string | hostname ]
Step 6
You can configure the remote ID as:
Example:
Switch(config)# ip dhcp snooping
• String of up to 63 ASCII characters (no spaces)
• Configured hostname for the switch
information option format remote-id
string acsiistring2
If the hostname is longer than 63 characters, it is truncated
to 63 characters in the remote-ID configuration.
Note
The default remote ID is the switch MAC address.
(Optional) If the switch is an aggregation switch connected to an edge
switch, this command enables the switch to accept incoming DHCP
snooping packets with option-82 information from the edge switch. ip dhcp snooping information option
allow-untrusted
Example:
Switch(config)# ip dhcp snooping
information option allow-untrusted
Step 7
The default setting is disabled.
Enter this command only on aggregation switches that are
connected to trusted devices. Note
Specifies the interface to be configured, and enter interface configuration
mode. interface interface-id
Example:
Switch(config)# interface
gigabitethernet2/0/1
Step 8
(Optional) Configures the circuit-ID suboption for the specified interface. ip dhcp snooping vlan vlan information
option format-type circuit-id
[ override ]
string ASCII-string
Step 9
Specify the VLAN and port identifier, using a VLAN ID in the range
of 1 to 4094. The default circuit ID is the port identifier, in the format
vlan-mod-port .
Example:
Switch(config-if)# ip dhcp snooping
You can configure the circuit ID to be a string of 3 to 63 ASCII
characters (no spaces).
vlan 1 information option format-type
curcuit-id override string ovrride2
(Optional) Use the
override
keyword when you do not want the
circuit-ID suboption inserted in TLV format to define subscriber
information.
Consolidated Platform Configuration Guide, Cisco IOS Release 15.2(4)E (Catalyst 2960-X Switches)
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How to Configure DHCP Features