H3C S9500 Series Operation Manual page 89

Operation Manual – DHCP
H3C S9500 Series Routing Switches
Note:
The DHCP client applies for an IP address through the DHCP relay agent. When the
packet from the DHCP client arrives at the DHCP relay agent, the DHCP relay agent
adds its primary IP address in the packet and forwards the packet to the DHCP
server. Upon receiving the packet, the DHCP server allocates an IP address in the
same segment as the IP address added by the DHCP relay agent.
If there is a local DHCP server, when the DHCP client applies for an IP address, it
can be assigned with only the address which is in the same network segment with
the primary IP address rather than a secondary IP address of the receiving interface
of the server.
If there is no local DHCP server, when a DHCP client applies for an IP address
through the relay agent, the DHCP client can be assigned with only an address
which is in the same network segment with the primary IP address rather than a
secondary IP address of the relay agent.
III. Releasing the IP address of a client through the DHCP relay agent
In some cases, you may have to manually release the IP address assigned to a client
through the DHCP relay agent. After this function is enabled, the DHCP relay agent will
actively send a release packet to the specified DHCP server. Upon receiving the packet,
the DHCP server will release the lease of the specified IP address.
IV. Releasing the IP address of a client through the DHCP relay agent in
system view
When configuring this function in system view:
If you specify no DHCP server, the DHCP relay agent will send a release packet to
all DHCP servers in the DHCP server groups corresponding to all the interfaces in
the DHCP relay agent mode.
If you specify a DHCP server, the DHCP relay agent will send a release packet to
the DHCP server.
Follow these steps to release the IP address of a client through the DHCP relay agent
in system view:
Enter system view
Request the DHCP server to
release the IP address assigned to
a client
To do...
3-4
Chapter 3 DHCP Relay Agent Configuration
Use the command...
system-view
dhcp relay release client-ip
client-mac [ server-ip ]
Remarks
—
Required