INS_CWGE24MS2_REV–
10/05/16 PAGE 124
INSTALLATION AND OPERATION MANUAL
CWGE24MS2
TECH SUPPORT: 1.888.678.9427
Web Configuration
Parameter
Description
State
Select this option to enable / disable the DHCP option 66 and
67 on the Switch.
TFTP IP
The TFTP server’s IP address gotten from the DHCP option 66.
TFTP File Name
The configuration filename gotten from the DHCP option 67.
Apply
Click Apply to save your changes to the Switch.
Refresh
Click Refresh to begin configuring this screen afresh.
Option 82
Introduction
DHCP Option 82 is the “DHCP Relay Agent Information Option”. Option 82 was designed to allow
a DHCP Relay Agent to insert circuit specific information into a request that is being forwarded to
a DHCP server. Specifically the option works by setting two sub-options: Circuit ID and Remote ID.
The DHCP option 82 is working on the DHCP snooping or/and DHCP relay.
The switch will monitor the DHCP packets and append some information as below to the
DHCPDISCOVER and DHCPREQUEST packets. The switch will remove the DHCP Option 82 from
the DHCPOFFER and DHCPACK packets. The DHCP server will assign IP domain to the client
dependent on these information.
The maximum length of the information is 32 characters.
In residential, metropolitan Ethernet-access environments, DHCP can centrally manage the IP
address assignments for a large number of subscribers. When the DHCP option-82 feature
is enabled on the switch, a subscriber device is identified by the switch port through which it
connects to the network (in addition to its MAC address). Multiple hosts on the subscriber LAN
can be connected to the same port on the access switch and are uniquely identified.
