3Com Switch 8800 Configuration Guide
Chapter 13 DHCP Configuration
13-5
Table 13-3
Configure the processing method for multiple VLAN interfaces
Operation
Command
Specify to forward DHCP packets to
local DHCP server and let the local
server assign IP addresses in global
address pools to DHCP clients
dhcp select
global
{
interface
vlan-interface
vlan
_
id
[
to
vlan-interface
vlan
_
id
] |
all
}
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
dhcp select
interface
{
interface
vlan-interface
vlan
_
id
[
to
vlan-interface
vlan
_
id
] |
all
}
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
dhcp select
relay
{
interface
vlan-interface
vlan
_
id
[
to
vlan-interface
vlan
_
id
] |
all
}
Revert to the default processing mode
undo dhcp select
{
interface
vlan-interface
vlan
_
id
[
to
vlan-interface
vlan
_
id
] |
all
}
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
Operation
Command
Enable fake DHCP server detection
dhcp server detect
Disable fake DHCP server detection
undo dhcp server detect
Fake DHCP server detection is disabled by default.