Ip Dhcp Snooping Information Option - Edge-Core ECS2100-10T Reference Manual

ip dhcp snooping
information option
switch receives any messages from a DHCP server, any packets received from
untrusted ports are dropped.
Example
This example enables DHCP snooping globally for the switch.
Console(config)#ip dhcp snooping
Console(config)#
Related Commands
ip dhcp snooping vlan (291)
ip dhcp snooping trust (295)
This command enables the use of DHCP Option 82 information for the switch, and
specifies the frame format to use for the remote-id when Option 82 information is
generated by the switch. Use the no form without any keywords to disable this
function, the no form with the encode no-subtype keyword to enable use of sub-
type and sub-length in CID/RID fields, or the no form with the remote-id keyword
to set the remote ID to the switch's MAC address encoded in hexadecimal.
Syntax

ip dhcp snooping information option

[encode no-subtype] [remote-id {ip-address [encode {ascii | hex}] |
mac-address [encode {ascii | hex}] | string string}]
no ip dhcp snooping information option [encode no-subtype]
[remote-id [ip-address encode] | [mac-address encode]]
encode no-subtype - Disables use of sub-type and sub-length fields in
circuit-ID (CID) and remote-ID (RID) in Option 82 information.
mac-address - Inserts a MAC address in the remote ID sub-option for the
DHCP snooping agent (that is, the MAC address of the switch's CPU).
ip-address - Inserts an IP address in the remote ID sub-option for the DHCP
snooping agent (that is, the IP address of the management interface).
encode - Indicates encoding in ASCII or hexadecimal.
string - An arbitrary string inserted into the remote identifier field.
(Range: 1-32 characters)
Default Setting
Option 82: Disabled
CID/RID sub-type: Enabled
Remote ID: MAC address (hexadecimal)
Command Mode
Global Configuration
Chapter 9
– 285 –
| General Security Measures
DHCPv4 Snooping