Specifying The Dhcp Server Selecting Algorithm - HPE FlexNetwork 10500 Series Configuration Manual

Step
1. Enter system view.
2. Enter interface view.
3. Enable the DHCP relay agent.
4. Return to system view.
5. Create a DHCP address pool
and enter its view.
6. Specify gateway addresses
for the clients matching the
DHCP address pool.
7. Specify DHCP servers for the
DHCP address pool.
8. Return to system view.
9. Enable the DHCP smart relay
feature.

Specifying the DHCP server selecting algorithm

The DHCP relay agent supports the DHCP server selecting algorithms polling and master-backup.
By default, the DHCP relay agent uses the polling algorithm. It forwards DHCP requests to all DHCP
servers. The DHCP clients select the DHCP server where the first received DHCP reply comes from.
If the DHCP relay agent uses the master-backup algorithm, it forwards DHCP requests to the
master DHCP server first. If the master DHCP server is not available, the relay agent forwards the
subsequent DHCP requests to a backup DHCP server. If the backup DHCP server is not available,
the relay agent selects the next backup DHCP server, and so on. If no backup DHCP server is
available, it repeats the process starting from the master DHCP server.
The master DHCP server is determined in one of the following ways:
•
In a common network where multiple DHCP server addresses are specified on the DHCP relay
interface, the first specified DHCP server is the master. The other DHCP servers are backup.
•
In a network where DHCP address pools are configured on the DHCP relay agent, the first
specified DHCP server in a DHCP address pool is the master. The other DHCP servers in the
DHCP address pool are backup.
The DHCP relay agent determines a DHCP server is not available if it does not receive any response
from the server within a period of time. This period of time is called the DHCP server response
timeout time. The DHCP server response timeout time is configurable and the default is 30 seconds.
If the DHCP relay agent selects a backup DHCP server, it does not switch back to the master DHCP
server by default. You can configure the DHCP relay agent to switch back to the master DHCP server
Command
system-view
interface interface-type
interface-number
dhcp select relay
quit
dhcp server ip-pool
pool-name
gateway-list
ip-address&<1-64>
[ export-route ]
remote-server
ip-address&<1-8>
quit
dhcp smart-relay enable
77
Remarks
N/A
N/A
By default, an interface operates in
the DHCP server mode when DHCP
is enabled.
N/A
By default, no DHCP address pool
exists.
By default, the DHCP address pool
does not have any gateway
addresses.
By default, the DHCP address pool
does not have any DHCP server IP
addresses.
You can specify a maximum of eight
DHCP servers for one DHCP
address pool for high availability.
The relay agent forwards
DHCP-DISCOVER and
DHCP-REQUEST packets to all
DHCP servers in the DHCP address
pool.
N/A
By default, the DHCP smart relay
feature is disabled.