Filter
Top Products
148 CHAPTER 11: DHCP RELAY CONFIGURATION
Actually, a DHCP relay enables DHCP clients and DHCP servers on different networks
to communicate with each other by forwarding the DHCP broadcasting packets
transparently between them.
DHCP Relay
Configuration
If a switch belongs to a fabric, you need to enable the UDP-helper function on it
before configure it to be a DHCP relay.
DHCP Relay
Configuration Tasks
Enabling DHCP Be sure to enable DHCP before you perform other DHCP relay-related configuration,
for other DHCP-related configurations cannot take effect with DHCP disabled.
Configuring an Interface
to Operate in DHCP
Relay Mode
There may be multiple DHCP servers deployed in one network. This increases the
reliability. Here, you can configure a DHCP server group containing one or multiple
DHCP servers.
You can configure an interface to forward DHCP packets received from DHCP clients
to a group of external DHCP server(s), so that the DHCP server(s) in this group can
assign IP addresses to the DHCP clients under this interface.
You can configure up to eight external DHCP IP addresses in a DHCP server group.
You can map multiple VLAN interfaces to one DHCP server group. But one VLAN
interface can be mapped to only one DHCP server group. If you execute the
dhcp-server groupNo command repeatedly, the new configuration overwrites the
previous one.
Table 133 DHCP relay configuration tasks
Operation Description Related section
Enable DHCP Required Enabling DHCP
Configure an interface to
operate in DHCP relay mode
Required Configuring an Interface to Operate in DHCP
Relay Mode
Configure DHCP relay security Required Configuring an Interface to Operate in DHCP
Relay Mode
Table 134 Enable DHCP
Operation Command Description
Enter system view system-view -
Enable DHCP dhcp enable Required
By default, DHCP is disabled.
Table 135 Configure an interface to operate in DHCP relay mode
Operation Command Description
Enter system view system-view -
Configure the DHCP server
IP address(es) in a specified
DHCP server group
dhcp-server groupNo
ip ip-address1 [
ipaddress-list ]
Required
By default, no DHCP server IP address is
configured in a DHCP server group.
Map an interface to a
DHCP server group
interface interface-type
interface-number
Required
By default, a VLAN interface is not mapped
to any DHCP server group.
dhcp-server groupNo