Enabling Client Offline Detection On The Dhcp Relay Agent; Configuring The Dhcp Relay Agent To Release An Ip Address; Configuring Option 82 - H3C SR8800-F Configuration Manual

Enabling client offline detection on the DHCP relay agent

The client offline detection on the DHCP relay agent detects the user online status based on the ARP
entry aging. When an ARP entry ages out, the DHCP client offline detection feature deletes the relay
entry for the IP address and sends a RELEASE message to the DHCP server.
The feature does not function if an ARP entry is manually deleted.
To enable client offline detection on the DHCP relay agent:
Step
1. Enter system view.
2. Enable the relay agent to
record relay entries.
3. Enter interface view.
4. Enable the DHCP relay agent.
5. Enable client offline detection.
Configuring the DHCP relay agent to release an
IP address
Configure the relay agent to release the IP address for a relay entry. The relay agent sends a
DHCP-RELEASE message to the server and meanwhile deletes the relay entry. Upon receiving the
DHCP-RELEASE message, the DHCP server releases the IP address.
To configure the DHCP relay agent to release an IP address:
Step
1. Enter system view.
2. Configure the DHCP relay
agent to release an IP
address.

Configuring Option 82

To support Option 82, you must perform related configuration on both the DHCP server and relay
agent. For DHCP server Option 82 configuration, see
To configure Option 82:
Step
1. Enter system view.
Command
system-view
dhcp relay
client-information record
interface interface-type
interface-number
dhcp select relay
dhcp client-detect
Command
system-view
dhcp relay release ip ip-address
[ vpn-instance
vpn-instance-name ]
"Enabling handling of Option
Command
system-view
141
Remarks
N/A
By default, the relay agent does not
record relay entries.
Without relay entries, client offline
detection cannot function correctly.
N/A
By default, when DHCP is enabled,
an interface operates in the DHCP
server mode.
By default, client offline detection is
disabled on the DHCP relay agent.
Remarks
N/A
This command can release only
the IP addresses in the recorded
relay entries.
82."
Remarks
N/A