39-5
To improve security and avoid malicious attacks to unused sockets, S4500 Ethernet switches provide
the following functions:
z
UDP port 67 and UDP port 68 ports used by DHCP are enabled only when DHCP is enabled.
z
UDP port 67 and UDP port 68 ports are disabled when DHCP is disabled.
The corresponding implementation is as follows:
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After DHCP is enabled with the
dhcp enable
command, if the DHCP server and DHCP relay agent
functions are not configured, UDP port 67 and UDP port 68 ports are kept disabled; if the DHCP
server or DHCP relay agent function is configured, UDP port 67 and UDP port 68 ports are
enabled.
z
After DHCP is disabled with the
undo dhcp enable
command, even if the DHCP server or DHCP
relay function is configured, UDP port 67 and UDP port 68 ports will be disabled.
Configuring the Global Address Pool Based DHCP Server
Configuration Task List
Complete the following tasks to configure the global address pool based DHCP server:
Task
Remarks
Enabling the Global Address Pool Mode on Interface(s)
Required
Creating a DHCP Global Address Pool
Required
Configuring the static IP address allocation
mode
Configuring an
Address Allocation
Mode for the Global
Address Pool
Configuring the dynamic IP address allocation
mode
One of the two options is
required
Only one mode can be
selected for the same
global address pool.
Configuring a Domain Name Suffix for the DHCP Client
Optional
Configuring DNS Servers for the DHCP Client
Optional
Configuring WINS Servers for the DHCP Client
Optional
Configuring Gateways for the DHCP Client
Optional
Configuring BIMS Server Information for the DHCP Client
Optional
Configuring Option 184 Parameters for the Client with Voice Service
Optional
Configuring the TFTP Server and Bootfile Name for the DHCP Client
Optional
Configuring a Self-Defined DHCP Option
Optional
Enabling the Global Address Pool Mode on Interface(s)
You can configure the global address pool mode on the specified or all interfaces of a DHCP server.
After that, when the DHCP server receives DHCP packets from DHCP clients through these interfaces,
it assigns IP addresses in the global address pool to the DHCP clients.
Follow these steps to configure the global address pool mode on interface(s):