Enabling/Disabling Fake Dhcp Server Detection - 3Com 8800 Configuration Manual

3Com Switch 8800 Configuration Guide
Table 13-3 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.

13.2.3 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 13-4 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
13-5
Chapter 13 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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