D-Link DGS-1250 Emulator - Page 142

ip dhcp snooping server-screen log-buffer

Page 142 highlights

DGS-1250 Series Gigabit Ethernet Smart Managed Switch CLI Reference Guide If the server IP address is not specified, it will enabled or disabled the DHCP server screen on the interface. By default, the DHCP server screen is disabled on all interfaces. If enabled, the DHCP server screen, on a specific interface, will filter all DHCP server packets from the interface and only forward trusted server packets. If a server screen entry is defined with a profile that contains a client MAC address, then the server message with the server IP address and the client addresses contained in the profile is forwarded. If an entry is defined without the client's MAC address, then the server message with the specified server IP address will be forwarded. Each server can only have one corresponding entry in the table. If the entry is defined with a profile but the entry does not exist, then messages with the server IP specified by the entry are not forwarded. Example This example shows how to configure a DHCP server screen profile named "campus-profile" and associate it with a DHCP server screen entry on port 3. Switch# configure terminal Switch(config)# dhcp-server-screen profile campus-profile Switch(config-dhcp-server-screen)# based-on hardware-address 00-08-01-02-03-04 Switch(config-dhcp-server-screen)# based-on hardware-address 00-08-01-03-00-01 Switch(config-dhcp-server-screen)# exit Switch(config)# interface eth1/0/3 Switch(config-if)# ip dhcp snooping server-screen 10.1.1.2 profile campus-profile Switch(config-if)# 16-21 ip dhcp snooping server-screen log-buffer This command is used to configure the DHCP server screen log buffer parameter. Use the no form of this command to revert to the default setting. ip dhcp snooping server-screen log-buffer entries NUMBER no ip dhcp snooping server-screen log-buffer entries Parameters NUMBER Specifies the buffer entry number. The maximum number is 1024. Default By default, this value is 32. Command Mode Global Configuration Mode. Usage Guideline Use this command to configure the maximum entry number of the log buffer. The DHCP server screen log buffer keeps tracks of the information of packets that did not pass the screening. The first packet that violates the check will be sent to the log module and recorded in the server screen log buffer. The subsequent packets belonging to the same session will not be sent to log module unless its record in the log buffer is cleared. If the log buffer is full but more violation events occur, packets will be discarded but the event will not be sent to the syslog module. If the user specifies a buffer size less than the current entry number, then the log buffer will automatically be cleared. 139

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DGS-1250 Series Gigabit Ethernet Smart Managed Switch CLI Reference Guide
139
If the server IP address is not specified, it will enabled or disabled the DHCP server screen on the interface. By
default, the DHCP server screen is disabled on all interfaces. If enabled, the DHCP server screen, on a specific
interface, will filter all DHCP server packets from the interface and only forward trusted server packets.
If a server screen entry is defined with a profile that contains a client MAC address, then the server message with
the server IP address and the client addresses contained in the profile is forwarded.
If an entry is defined without the client’s MAC address, then the server message with the specified server IP
address will be forwarded. Each server can only have one corresponding entry in the table.
If the entry is defined with a profile but the entry does not exist, then messages with the server IP specified by the
entry are not forwarded.
Example
This example shows how to configure a DHCP server screen profile nam
ed “campus
-
profile” and associate it with
a DHCP server screen entry on port 3.
Switch# configure terminal
Switch(config)# dhcp-server-screen profile campus-profile
Switch(config-dhcp-server-screen)# based-on hardware-address 00-08-01-02-03-04
Switch(config-dhcp-server-screen)# based-on hardware-address 00-08-01-03-00-01
Switch(config-dhcp-server-screen)# exit
Switch(config)# interface eth1/0/3
Switch(config-if)# ip dhcp snooping server-screen 10.1.1.2 profile campus-profile
Switch(config-if)#
16-21
ip dhcp snooping server-screen log-buffer
This command is used to configure the DHCP server screen log buffer parameter. Use the
no
form of this
command to revert to the default setting.
ip dhcp snooping server-screen log-buffer entries
NUMBER
no ip dhcp snooping server-screen log-buffer entries
Parameters
NUMBER
Specifies the buffer entry number. The maximum number is 1024.
Default
By default, this value is 32.
Command Mode
Global Configuration Mode.
Usage Guideline
Use this command to configure the maximum entry number of the log buffer. The DHCP server screen log buffer
keeps tracks of the information of packets that did not pass the screening. The first packet that violates the check
will be sent to the log module and recorded in the server screen log buffer. The subsequent packets belonging to
the same session will not be sent to log module unless its record in the log buffer is cleared.
If the log buffer is full but more violation events occur, packets will be discarded but the event will not be sent to the
syslog module. If the user specifies a buffer size less than the current entry number, then the log buffer will
automatically be cleared.