User guide

77User Guide InfraStruxure 150kVA Power Distribution Unit
DHCP response options
Each valid DHCP response contains options that provide the TCP/IP settings that the PDU needs to
operate on a network, and other information that affects the operation of the PDU.
Vendor Specific Information (option 43). The PDU uses this option in a DHCP response to
determine whether the DHCP response is valid. This option contains up to two APC-specific options in a
TAG/LEN/DATA format: the APC Cookie and the Boot Mode Transition.
• APC Cookie. Tag 1, Len 4, Data “1APC”
Option 43 communicates to the PDU that a DHCP server is configured to service APC
devices. By default, this DHCP response option must contain the APC cookie for the PDU to
accept the lease.
To disable the requirement of an APC cookie, see “DHCP” on page 30.
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
• Boot Mode Transition. Tag 2, Len 1, Data 1/2
This option 43 setting enables or disables Remain in DHCP & BOOTP mode after
accepting TCP/IP settings, which, by default, is disabled.
• A data value of 1 enables Remain in DHCP & BOOTP mode after accepting TCP/IP
settings. Whenever the PDU reboots, it will request its network assignment first from a
BOOTP server, and then, if necessary, from a DHCP server.
• A data value of 2 disables the option Remain in DHCP & BOOTP mode after accepting
TCP/IP settings option. The TCP/IP Configuration setting option switches to DHCP
when the PDU accepts the DHCP response. Whenever the PDU reboots, it will request its
network assignment from a DHCP server only.
Following, in hexadecimal format, is an example of a Vendor Specific Information option that
contains the APC cookie and the disable setting for Boot Mode Transition:
Option 43 = 0x01 0x04 0x31 0x41 0x50 0x43 0x02 0x01 0x01
TCP/IP options. The PDU uses the following options within a valid DHCP response to define its TCP/
IP settings. All of these options except the first are described in RFC2132.
• IP Address (from the yiaddr field of the DHCP response, described in RFC2131): The IP
address that the DHCP server is leasing to the PDU.
• Subnet Mask (option 1): The Subnet Mask value that the PDU needs to operate on the network.
• Router, i.e., Default Gateway (option 3): The default gateway address that the PDU needs to
operate on the network.
• IP Address Lease Time (option 51): The time duration for the lease of the IP Address to the
PDU.
• Renewal Time, T1 (option 58): The time that the PDU must wait after an IP address lease is
assigned before it can request a renewal of that lease.
• Rebinding Time, T2 (option 59): The time that the PDU must wait after an IP address lease is
assigned before it can seek to rebind that lease.