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Step
7.
Specify DHCP servers for the
DHCP address pool.
8.
Return to system view.
9.
Enable the DHCP smart relay
feature.
Specifying the source IP address for DHCP
requests
This task is required if multiple relay interfaces share the same IP address or if a relay interface does
not have routes to DHCP servers. You can perform this task to specify an IP address or the IP
address of another interface, typically the loopback interface, on the DHCP relay agent as the source
IP address for DHCP requests.
If you specify the ip-address argument, the relay agent changes not only the source IP address but
also the giaddr field of a DHCP request. The DHCP server assigns the client an IP address on the
same subnet as the specified IP address in the giaddr field. As a result, the client might not be on the
same subnet as the DHCP relay interface (the gateway). To avoid this problem, you must configure
Option 82 on the relay interface before specifying the ip-address argument. This configuration
enables the DHCP relay agent to insert the primary IP address of the relay interface in Option 82.
Based on this option, the DHCP server assigns an IP address on the same subnet as the IP address
of the relay interface. The DHCP relay agent looks up the MAC address table for the output interface
to forward the DHCP reply packets.
If you specify gateway, the relay agent uses the IP address in the giaddr field as the source IP
address. If the giaddr field is empty, the relay agent follows the default rule to specify the source IP
address for DHCP requests.
If you specify relay-interface, the relay agent uses the primary IP address of the relay interface as
the source IP address. If this interface does not have an IP address, the relay agent follows the
default rule to specify the source IP address for DHCP requests.
To specify the source IP address for DHCP requests:
Step
1.
Enter system view.
2.
Enter interface view.
Command
remote-server
ip-address&<1-8>
quit
dhcp smart-relay enable
Command
system-view
interface interface-type
interface-number
145
Remarks
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.
Remarks
N/A
N/A
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Troubleshooting
