PLANET XGS3-24042 - Manual (Page 459)

30-98
Considering the limited hardware resources of the switch, the actual number of trust users
distributed depends on the resource amount. If a bigger max number of users is set using this
command, DHCP Snooping will distribute the binding informaiton of untrust users to hardware to be
trust users as long as there is enough available resources. Otherwise, DHCP Snooping will change
the distributed binging informaiton accordint to the new smaller max user number. When the
number of distributed bingding informaiton entries reaches the max limit, no new DHCP will be able
to become trust user or to access other network resouces via the switch.
Examples:
Enable DHCP Snooping binding user funtion on Port ethernet1/0/1, setting the max number of user
allowed to access by Port Ethernet1/0/1 as 5.
Switch(Config-If-Ethernet1/0/1)# ip dhcp snooping binding user-control max-user 5
Related Command:
ip dhcp snooping binding user-control
30.16 ip dhcp snooping information enable
Command:
ip dhcp snooping information enable
no ip dhcp snooping information enable
Function:
This command will enable option 82 function of DHCP Snooping on the switch, the no operation of
this command will disable that function.
Default Settings:
Option 82 function is disabled in DHCP Snooping by default.
Command Mode:
Global Configuration Mode.
Usage Guide:
Only by implementing this command, can DHCP Snooping add standard option 82 to DHCP request
messages and forward the message. The format of option1 in option 82 (Circuit ID option) is
standard vlan name plus physical port name, like “vlan1+ethernet1/12”. That of option2 in option 82
(remote ID option) is CPU MAC of the switch, like “00030f023301”. If a DHCP request message with
option 82 options is received, DHCP Snooping will replace those options in the message with its
own. If a DHCP reply message with option 82 options is received, DHCP Snooping will dump those
options in the message and forward it. This command and “ip dhcp snooping option82 enable”
command are mutually exclusive.
Examples:
Enable option 82 function of DHCP Snooping on the switch.