LevelOne GEL-5261, User Manual

Page: 313 / 570

Chapter 12
| Security Measures
DHCP Snooping
– 313 –
DHCP Snooping
Global Configuration
Use the Security > DHCP Snooping (Configure Global) page to enable DHCP
Snooping globally on the switch, or to configure MAC Address Verification.
Parameters
These parameters are displayed:
General
◆
DHCP Snooping Status – Enables DHCP snooping globally. (Default: Disabled)
◆ DHCP Snooping MAC-Address Verification – Enables or disables MAC
address verification. If the source MAC address in the Ethernet header of the
packet is not same as the client's hardware address in the DHCP packet, the
packet is dropped. (Default: Enabled)
Information
◆ DHCP Snooping Information Option Status – Enables or disables DHCP
Option 82 information relay. (Default: Disabled)
◆
DHCP Snooping Information Option Sub-option Format – Enables or
disables use of sub-type and sub-length fields in circuit-ID (CID) and remote-ID
(RID) in Option 82 information. (Default: Enabled)
◆
DHCP Snooping Information Option Remote ID – Specifies the MAC address, IP
address, or arbitrary identifier of the requesting device (i.e., the switch in this
context).
■
MAC Address – Inserts a MAC address in the remote ID sub-option for the
DHCP snooping agent (i.e., the MAC address of the switch ’s CPU). This
attribute can be encoded in Hexadecimal or ASCII.
■
IP Address – Inserts an IP address in the remote ID sub-option for the
DHCP snooping agent (i.e., the IP address of the management interface).
This attribute can be encoded in Hexadecimal or ASCII.
■
string - An arbitrary string inserted into the remote identifier field.
(Range: 1-32 characters)
◆
DHCP Snooping Information Option Remote ID TR101 VLAN Field – Adds
“:VLAN” in TR101 field for untagged packets.
The format for TR101 option 82 is: “<IP> eth <SID>/<PORT>[:<VLAN>]”. Note
that the SID (Switch ID) is always 0. By default the PVID is added to the end of
the TR101 field for untagged packets. For tagged packets, the VLAN ID is always
added.