ISCSI Boot
NetXtreme-E User’s Manual
February 26, 2018 • NetXtreme-E-UG100
Page 54
Configuring the DHCP Server to Support iSCSI Boot
The DHCP server is an optional component and it is only necessary for dynamic iSCSI Boot configuration setup
(see
“Dynamic iSCSI Boot Configuration” on page 52
).
Configuring the DHCP server to support iSCSI boot is different for IPv4 and IPv6. Refer to the following sections:
DHCP iSCSI Boot Configurations for IPv4
The DHCP protocol includes a number of options that provide configuration information to the DHCP client. For
iSCSI boot, Broadcom adapters support the following DHCP configurations:
DHCP Option 17, Root Path
Option 17 is used to pass the iSCSI target information to the iSCSI client. The format of the root path as defined
in IETC RFC 4173 is:
iscsi:"<servername>":"<protocol>":"<port>":"<LUN>":"<targetname>
The parameters are defined in
DHCP Option 43, Vendor-Specific Information
DHCP option 43 (vendor-specific information) provides more configuration options to the iSCSI client than
DHCP option 17. In this configuration, three additional suboptions are provided that assign the initiator IQN to
the iSCSI boot client along with two iSCSI target IQNs that can be used for booting. The format for the iSCSI
target IQN is the same as that of DHCP option 17, while the iSCSI initiator IQN is simply the initiator's IQN.
The suboptions are listed below.
Table 32: DHCP Option 17 Parameter Definition
Parameter
Definition
"iscsi:"
A literal string.
<servername>
The IP address or FQDN of the iSCSI target
":"
Separator.
<protocol>
The IP protocol used to access the iSCSI target. Currently, only TCP is supported so
the protocol is 6.
<port>
The port number associated with the protocol. The standard port number for iSCSI is
3260.
<LUN>
The Logical Unit Number to use on the iSCSI target. The value of the LUN must be
represented in hexadecimal format. A LUN with an ID OF 64 would have to be
configured as 40 within the option 17 parameter on the DHCP server.
<targetname>
The target name in either IQN or EUI format (refer to RFC 3720 for details on both IQN
and EUI formats). An example IQN name would be "iqn.1995-05.com.broadcom:iscsi-
target".
Note:
DHCP Option 43 is supported on IPv4 only.
