H3C Technologies H3C S12500 Series Switches - Manual (Page 68)

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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 Command Remarks
1. Enter system view. system-view N/A
2. Configure the DHCP relay
agent to release an IP
address.
dhcp relay release ip client-ip
[ vpn-instance vpn-instance-name ]
This command can release only the
IP addresses in the recorded relay
entries.
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Configuring Option 82
Follow these guidelines when you configure 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 "
707H
Enabling handling of Option 82 ."
• The system name (sysname) if padded in sub-option 1 (node identifier) of Option 82 must not
contain spaces. Otherwise, the DHCP relay agent drops the message.
To configure Option 82:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter interface view.
interface interface-type
interface-number
N/A
3. Enable the relay agent to handle
Option 82.
dhcp relay information enable
By default, handling of
Option 82 is disabled.
4. (Optional.) Configure the strategy
for handling DHCP requests
containing Option 82.
dhcp relay information strategy
{ drop | keep | replace } By default, the handling
strategy is replace.
5. (Optional.) Configure the padding
content and code type for the
circuit ID sub-option.
dhcp relay information circuit-id
{ string circuit-id | { normal |
verbose [ node-identifier { mac |
sysname | user-defined
node-identifier } ] } [ format { ascii |
hex } ] }
By default, the padding
format for circuit ID
sub-option is normal, and the
code type is hex.
6. (Optional.) Configure the padding
content and code type for the
remote ID sub-option.
dhcp relay information remote-id
{ normal [ format { ascii | hex } ] |
string remote-id | sysname }
By default, the padding
format for the remote ID
sub-option is normal, and the
code type is hex.