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Chapter 20 Commands for DHCP
Snooping option 82
20.1 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.
Parameters: None.
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.
Examples: Enable option 82 function of DHCP Snooping on the switch.
Switch(config)#ip dhcp snooping enable
Switch(config)#ip dhcp snooping binding enable
Switch(config)#ip dhcp snooping information enable
Chapter 21 IPv4 Multicast Protocol
21.1 Commands for DCSCM
21.1.1 access-list (Multicast Destination Control)