Configuring The Dhcp Relay Agent To Send A Dhcp-Release Request; Configuring The Dhcp Relay Agent Security Functions - 3Com MSR 50 Series Configuration Manual

Configuring the DHCP
Relay Agent to Send a
DHCP-Release Request
Configuring the DHCP
Relay Agent Security
Functions
n
Sometimes, you need to release a client's IP address manually on the DHCP relay
agent. With this task completed, the DHCP relay agent can actively send a
DHCP-RELEASE request that contains the client's IP address to be released. Upon
receiving the DHCP-RELEASE request, the DHCP server then releases the IP address
for the client.
To configure the DHCP relay agent to send a DHCP-RELEASE request, use the
following commands:
To do...
Enter system view
Configure the DHCP relay agent to send a
DHCP-RELEASE request
Creating static bindings and enable invalid IP address check
The DHCP relay agent can dynamically record clients' IP-to-MAC bindings to
generate a dynamic binding after clients got IP addresses. It also supports static
binding, which means you can manually configure IP-to-MAC bindings on the
DHCP relay agent, so that users can access external network using fixed IP
addresses.
For avoidance of invalid IP address configuration, you can configure the DHCP
relay agent to check whether a requesting client's IP and MAC addresses match a
binding on it (both dynamic and static bindings). If not, the client cannot access
outside networks via the DHCP relay agent.
To create a static binding and enable invalid IP address check, use the following
commands:
To do...
Enter system view
Create a static binding
Enter interface view
Enable invalid IP address
check
The dhcp relay address-check command can be executed only on Layer 3
■
Ethernet interfaces (including sub-interfaces) and VLAN interfaces.
The dhcp relay address-check enable command is independent of other
■
commands of the DHCP relay agent. That is, the invalid address check takes
effect when this command is executed, regardless of whether other commands
are used.
You are recommended to configure IP address check on the interface enabled
■
with the DHCP relay agent; otherwise, the valid DHCP clients may not be
capable of accessing networks.
Configuring the DHCP Relay Agent
Use the command...
system-view
dhcp relay release ip
client-ip
Use the 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 }
593
Remarks
-
Required
Remarks
-
Optional
No static binding is created by
default
-
Required
Disabled by default