Dhcp Relay Configuration; Dhcp Relay Configuration Tasks; Enabling Dhcp; Configuring An Interface To Operate In Dhcp Relay Mode - 3Com 5500-SI Configuration Manual

148 C 11: DHCP R
HAPTER
DHCP Relay
Configuration
DHCP Relay
Configuration Tasks

Enabling DHCP

Configuring an Interface
to Operate in DHCP
Relay Mode
C
ELAY ONFIGURATION
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.
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.
Table 133 DHCP relay configuration tasks
Operation
Enable DHCP
Configure an interface to
operate in DHCP relay mode
Configure DHCP relay security
Be sure to enable DHCP before you perform other DHCP relay-related configuration,
for other DHCP-related configurations cannot take effect with DHCP disabled.
Table 134 Enable DHCP
Operation
Enter system view
Enable DHCP
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.
Table 135 Configure an interface to operate in DHCP relay mode
Operation
Enter system view
Configure the DHCP server
IP address(es) in a specified
DHCP server group
Map an interface to a
DHCP server group
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.
Description Related section
Required Enabling DHCP
Required Configuring an Interface to Operate in DHCP
Relay Mode
Required Configuring an Interface to Operate in DHCP
Relay Mode
Command Description
system-view -
dhcp enable Required
By default, DHCP is disabled.
Command
system-view
dhcp-server groupNo
ip ip-address1 [
ipaddress-list ]
interface interface-type
interface-number
dhcp-server groupNo
Description
-
Required
By default, no DHCP server IP address is
configured in a DHCP server group.
Required
By default, a VLAN interface is not mapped
to any DHCP server group.