User`s guide

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USER’S GUIDE AUTOMATIC TRANSFER SWITCH
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DHCP response options
Each valid DHCP response contains options that provide the TCP/IP
settings that the Automatic Transfer Switch needs to operate on a network,
and other information that affects the operation of the Automatic Transfer
Switch.
The Automatic Transfer Switch uses the Vendor Specific Information option
(option 43) in a DHCP response to determine whether the DHCP response
is valid.
Vendor Specific Information (option 43). The Vendor Specific
Information option contains up to two APC specific options encapsulated in
a TAG/LEN/DATA format: the APC cookie and the Boot Mode Transition.
APC Cookie. Tag 1, Len 4, Data “1APC”. Option 43 notifies the Automatic
Transfer Switch that a DHCP server has been configured to service APC
devices. By default, the APC cookie must be present in this DHCP response
option before the Automatic Transfer Switch can accept the lease.
Following, in hexadecimal format, is an example of a Vendor Specific
Information option that contains the APC cookie:
Option 43 = 0x01 0x04 0x31 0x41 0x50 0x43
Use the DHCP Cookie Is setting described in Automatic Transfer
Switch settings to disable the APC cookie requirement.