R3166-R3206-HP High-End Firewalls Network Management Configuration Guide-6PW101

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Item Description
Dynamic Bindings
Refresh
Enable or disable periodic refresh of dynamic client entries, and set the refresh
interval.
Via the DHCP relay agent, a DHCP client sends a DHCP-RELEASE unicast message
to the DHCP server to relinquish its IP address. In this case the DHCP relay agent
simply conveys the message to the DHCP server, thus it does not remove the IP
address from dynamic client entries. To solve this problem, the periodic refresh of
dynamic client entries feature is introduced.
With this feature, the DHCP relay agent uses the IP address of a client and the MAC
address of the DHCP relay agent interface to periodically send a DHCP-REQUEST
message to the DHCP server.
• If the server returns a DHCP-ACK message or does not return any message within
a specified interval, which means that the IP address is assignable now, the
DHCP relay agent will age out the client entry.
• If the server returns a DHCP-NAK message, which means the IP address is still in
use, the relay agent will not age it out.
If the Auto radio button is clicked on, the refresh interval is calculated by the relay
agent according to the number of client entries.
Track Timer Interval
Return to DHCP relay agent configuration task list.
Creating a DHCP server group
Select Network > DHCP > DHCP Relay from the navigation tree to enter the page shown in Figure 67. In
the Server Group field, click Add to enter the page shown in Figure 68.
Figure 68 Create a server group
Table 27 DHCP server group configuration items
Item Description
Server Group ID
Type the ID of a DHCP server group.
You can create up to 20 DHCP server groups.
IP Address
Type the IP address of a server in the DHCP server group.
The server IP address cannot be on the same subnet as the IP address of the
DHCP relay agent; otherwise, the client cannot obtain an IP address.
Return to DHCP relay agent configuration task list.