H3C S9500 Series Operation Manual page 174

Operation Manual – Network Protocol
H3C S9500 Series Routing Switches
Table 4-3 Configure the processing method for multiple VLAN interfaces
Specify to forward DHCP packets to
local DHCP server and let the local
server assign IP addresses in global
address pools to DHCP clients
Specify to forward DHCP packets to
local DHCP server and let the local
server assign IP addresses in VLAN
interface address pool to DHCP clients
Specify to forward DHCP packets to
remote DHCP servers. In this case, the
current switch operates as a DHCP
relay, and IP addresses are assigned by
DHCP servers located in other networks
Revert to the default processing mode
By default, DHCP packets are processed in global method. That is, DHCP packets are
forwarded to local DHCP server and IP addresses in global address pools are
assigned.
4.2.3 Enabling/Disabling Fake DHCP Server Detection
If an unauthorized DHCP server exists in a network, it also answers when users in the
network request IP addresses, and then interacts with the DHCP clients. This causes
that the users cannot obtain correct IP addresses to access network. This kind of
DHCP servers are known as fake DHCP servers.
With fake DHCP server detection enabled, the switch can record information (such as
the IP addresses) about the DHCP servers. This helps administrators to detect fake
DHCP servers in time and take proper measures.
Perform the following configuration in system view.
Table 4-4 Enable/Disable fake DHCP server detection
Enable fake DHCP server detection
Disable fake DHCP server detection
Fake DHCP server detection is disabled by default.
Operation
Operation
4-6
Chapter 4 DHCP Configuration
Command
dhcp select global
vlan-interface vlan-id
vlan-interface vlan-id ] | all }
dhcp select interface { interface
vlan-interface vlan-id
vlan-interface vlan-id ] | all }
dhcp select relay
vlan-interface vlan-id
vlan-interface vlan-id ] | all }
undo dhcp select
vlan-interface vlan-id
vlan-interface vlan-id ] | all }
Command
dhcp server detect
undo dhcp server detect
{ interface
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