Correlating A Dhcp Server Group With A Relay Agent Interface - H3C S5120-SI Series Operation Manual

To do...
Enable the DHCP relay agent
on the current interface
If the DHCP client obtains an IP address via the DHCP relay agent, the address pool of the subnet to
which the IP address of the DHCP relay agent belongs must be configured on the DHCP server.
Otherwise, the DHCP client cannot obtain a correct IP address.

Correlating a DHCP Server Group with a Relay Agent Interface

To improve reliability, you can specify several DHCP servers as a group on the DHCP relay agent and
correlate a relay agent interface with the server group. When the interface receives requesting
messages from clients, the relay agent will forward them to all the DHCP servers of the group.
Follow these steps to correlate a DHCP server group with a relay agent interface:
To do...
Enter system view
Create a DHCP server group
and add a server into the group
Enter interface view
Correlate the DHCP server
group with the current interface
You can specify up to twenty DHCP server groups on the relay agent and up to eight DHCP server
addresses for each DHCP server group.
The IP addresses of DHCP servers and those of relay agent's interfaces cannot be on the same
subnet. Otherwise, the client cannot obtain an IP address.
A DHCP server group can correlate with one or multiple DHCP relay agent interfaces, while a relay
agent interface can only correlate with one DHCP server group. Using the dhcp relay
server-select command repeatedly overwrites the previous configuration. However, if the
specified DHCP server group does not exist, the interface still uses the previous correlation.
The group-id argument in the dhcp relay server-select command is configure by using the dhcp
relay server-group command.
Use the command...
dhcp select relay
Use the command...
system-view
dhcp relay server-group group-id
ip ip-address
interface interface-type
interface-number
dhcp relay server-select group-id
1-4
Remarks
Required
With DHCP enabled, interfaces
work in the DHCP server mode.
Remarks
—
Required
Not created by default.
—
Required
By default, no interface is
correlated with any DHCP
server group.