40-7
z
ck en
dent
of the DHCP relay
ddress check takes effect when this command is executed, regardless
a
o e
P) are used.
z
d
ble
command
configure the static binding of the IP addre
server. Otherwise, the DHCP client will fail to obtain an IP address.
The
address-che
able
command is indepen
of other commands
agent. That is, the invalid a
of whether other comm
Before executing the
a
server, you need to
nds (such as the command t
dress-check ena
nable DHC
on the interface connected to the DHCP
ss to the MAC address of the DHCP
Configuring the d
e DHCP server to the DHCP client, the DHCP relay agent can
automatically record the client’s IP-to-MAC binding and generate a dynamic address entry. But as a
HCP relay agent does not process DHCP-RELEASE packets, which are sent to DHCP servers by
s release IP addresses, the user address entries
You can solve this problem by enabling the DHCP
ake packet (the
fied period, the IP address can be assigned. The DHCP
ss table.
z
If the DHCP r
ceives the DH
e IP
address d
ut the corre
ry.
Follo
nfigure the
address entry upda
n:
ynamic client address entry updating function
After relaying an IP address from th
D
DHCP clients through unicast when the DHCP client
maintained by the DHCP cannot be updated in time.
relay agent handshake function and configuring the dynamic client address entry updating interval.
After the handshake function is enabled, the DHCP relay agent sends the handsh
DHCP-REQUEST packet) periodically to the DHCP server using a client’s IP address and its own MAC
address.
z
If the DHCP relay agent receives the DHCP-ACK packet from the DHCP server, or receives no
response from the server within a speci
relay agent ages out the corresponding entry in the client addre
elay agent re
oes not expire. The DHCP rel
CP-NAK packet from the DHCP serve
ay agent does not age o
r, the lease of th
sponding ent
w these steps to co
dynamic user
ting functio
To do…
Use the command…
Remarks
Enter system view
system-view
—
Enable the
agent hand
function
DHCP relay
shake
dhcp relay hand enable
Optional
Enabled by default.
Set the interval at which
the DHCP relay agent
dynamically updates the
client address entries
dhcp-security tracker
{
interval
|
auto
}
Optional
By default,
auto
is adopted, that is, the
interval is automatically calculated.
Currently, the DHCP relay agent handshake function on an S4500 series switch can only interoperate
s 2000 DHCP server.
with a Window
