Configuring Periodic Refresh Of Dynamic Client Entries; Enabling Unauthorized Dhcp Server Detection - HP 830 Series Configuration Manual

The dhcp relay address-check enable command only checks IP and MAC addresses but not
•
interfaces.
When using the dhcp relay security static command to bind an interface to a static binding entry,
•
make sure the interface is configured as a DHCP relay agent. Otherwise, address entry conflicts
may occur.
Configuration procedure
To create a static binding and enable address check:
Step
1. Enter system view.
2. Create a static binding.
3. Enter interface view.
4. Enable or disable address
check.

Configuring periodic refresh of dynamic client entries

A DHCP client unicasts a DHCP-RELEASE message to the DHCP server to release its IP address. The
DHCP relay agent simply conveys the message to the DHCP server and does not remove the IP-to-MAC
entry of the client.
With this feature, the DHCP relay agent uses the IP address of a client and the MAC address of the DHCP
relay 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 specific interval,
the DHCP relay agent ages out the entry.
If the server returns a DHCP-NAK message, the relay agent keeps the entry.
•
To configure periodic refresh of dynamic client entries:
Step
1. Enter system view.
2. Enable periodic refresh of
dynamic client entries.
Configure the refresh interval.
3.

Enabling unauthorized DHCP server detection

Unauthorized DHCP servers may assign wrong IP addresses to DHCP clients.
Command
system-view
dhcp relay security static ip-address
mac-address [ interface
interface-type interface-number ]
interface interface-type
interface-number
dhcp relay address-check { disable |
enable }
Command
system-view
dhcp relay security refresh
enable
dhcp relay security tracker
{ interval | auto }
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Remarks
N/A
Optional.
No static binding is created by
default.
N/A
Disabled by default.
Remarks
N/A
Optional.
Enabled by default.
Optional.
The default setting is auto. The auto
interval is calculated by the relay agent
according to the number of client entries.