Configuring An Interface To Operate In Dhcp Relay Mode - Huawei Quidway S3900 Series Operation Manual

Operation Manual - DHCP
Quidway S3900 Series Ethernet Switches-Release 1510

3.2.3 Configuring an Interface to Operate in DHCP Relay Mode

When an interface operates in the relay mode, the interface forwards the DHCP
packets received from DHCP clients to an external DHCP server, which assigns IP
addresses to the DHCP clients.
To enhance reliability, you can set multiple DHCP servers on the same network. These
DHCP servers form a DHCP server group. When the interface establishes mapping
relationship with the DHCP server group, the interface forwards the DHCP packets to
all servers in the server group.
Table 3-3 Configure an interface to operate in DHCP relay mode
Operation
Enter system view
Configure
DHCP server IP
address(es) in a
specified
server group
Map an interface
to a DHCP server
group
Note:
To prevent malicious attacks to unused sockets and enhance security, S3900 series
Ethernet switches provide the following functions:
When DHCP is enabled, sockets UDP 67 and UDP 68 used by DHCP are enabled.
When DHCP is disabled, sockets UDP 67 and UDP 68 are disabled at the same
time.
The preceding functions are implemented as follows:
After you configure a DHCP server group by using the dhcp-server command,
sockets UDP 67 and UDP 68 will be enabled.
After you delete the DHCP server group by using the undo dhcp-server command
and disable all the DHCP functions, sockets UDP 67 and UDP 68 will be disabled.
Command
system-view
the
dhcp-server
ip-address&<1-8>
DHCP
interface
interface-number
dhcp-server groupNo
Huawei Technologies Proprietary
3-5
Chapter 3 DHCP Relay Configuration
—
Required
groupNo ip
By default, no DHCP server
IP address is configured in a
DHCP server group
interface-type
Required
By default, a VLAN interface
is not mapped to any DHCP
server group
Description