Preparing For Configurations; Default Configurations Of Dhcp Snooping; Configuring Dhcp Snooping - Raisecom ISCOM2600G-HI (A) Series Configuration Manual

Raisecom
ISCOM2600G-HI (A) Series Configuration Guide



6.3.2 Preparing for configurations

Scenario
DHCP Snooping is a security feature of DHCP, used to make DHCP client obtain its IP
address from a legal DHCP server and record mapping between IP address and MAC address
of a DHCP client.
The Option field of a DHCP packet records location of a DHCP client. The administrator can
locate a DHCP client through the Option field and control client security and accounting. The
device configured with DHCP Snooping and Option can perform related process according to
Option field status in the packet.
Prerequisite
N/A

6.3.3 Default configurations of DHCP Snooping

Default configurations of DHCP Snooping are as below.
Global DHCP Snooping status
Interface DHCP Snooping status
Interface trusted/untrusted status
DHCP Snooping in support of Option 82

6.3.4 Configuring DHCP Snooping

Generally, you must ensure that the ISCOM2600G-HI series switch interface connected to
DHCP server is in trusted status while the interface connected to the user is in untrusted status.
If enabled with DHCP Snooping but without the feature of DHCP Snooping supporting DHCP
Option, the ISCOM2600G-HI series switch will do nothing to Option fields in packets. For
packets without Option fields, the ISCOM2600G-HI series switch does not conduct the
insertion operation.
By default, DHCP Snooping is enabled on all interfaces, but only when global DHCP
Snooping is enabled can interface DHCP Snooping take effect.
Configure DHCP Snooping for the ISCOM2600G-HI series switch as below.
When the ISCOM2600G-HI series switch receives a DHCP request packet, it processes
packets according to Option field included or not, filling mode, and processing policy
configured by user, then forwards the processed packet to DHCP server.
When the ISCOM2600G-HI series switch receives a DHCP reply packet, it deletes the
Optional field and forwards the rest part of the packet to the DHCP client if the packet
contains the Option field, or it forwards the packet directly if the packet does not contain
the Option field.
Function
Raisecom Proprietary and Confidential
Copyright © Raisecom Technology Co., Ltd.
6 DHCP
Default value
Disable
Enable
Untrust
Disable
266