SAN URIs

When booting from SAN, you can specify the location of the SAN target using a SAN URI. For example, when using the sanboot command in an iPXE script:

  #!ipxe
  sanboot iscsi:10.253.235.1::::iqn.2010-04.org.ipxe:rabbit

or as the root-path DHCP option (using ISC dhcpd):

  option root-path "iscsi:10.253.253.1::::iqn.2010-04.org.ipxe:rabbit";

or as the root-path DHCP option (using the Microsoft DHCP server):

The format of the SAN URI depends upon the SAN protocol that you are using.

The format of an iSCSI SAN URI is defined by RFC 4173. The general syntax is:

  iscsi:<servername>:<protocol>:<port>:<LUN>:<targetname>

For example:

  iscsi:10.253.235.1::::iqn.2010-04.org.ipxe:rabbit
  iscsi:boot.ipxe.org::::iqn.2010-04.org.ipxe.boot:public
  iscsi:192.168.0.1:::1:iqn.1991-05.com.microsoft:msdos622-target
  iscsi:opensolaris.home::::iqn.1986-03.com.sun:02:e9abf4cd-714b-c6ec-d017-eea5a56252ed

• <servername> is the DNS name or IP address of the iSCSI target.
• <protocol> is ignored and can be left empty.¹⁾
• <port> is the TCP port of the iSCSI target. It can be left empty, in which case the default port (3260) will be used.
• <LUN> is the SCSI LUN of the boot disk, in hexadecimal. It can be left empty, in which case the default LUN (0) will be used.
• <targetname> is the iSCSI target IQN.

If you are using iSCSI authentication, then you will need to configure the username and password settings (and possibly also the reverse-username and reverse-password settings) before attempting to connect to the SAN target. There is no way to specify usernames and passwords directly within the iSCSI SAN URI.

The format of an AoE SAN URI is:

  aoe:e<n>.<m>

For example:

  aoe:e0.0
  aoe:e0.1
  aoe:e2.4

• <n> is the AoE major device number (also known as the shelf number).
• <m> is the AoE minor device number (also known as the slot number).

There is no way to specify a particular network device within the AoE SAN URI. iPXE will use the most recently opened network device.

The format of an HTTP SAN URI is simply a standard HTTP URI. For example:

  http://boot.ipxe.org/freedos/fdfullcd.iso

Note that the HTTP server must support range requests, otherwise SAN booting will fail.

The format of an FCP SAN URI is:

  fcp:<wwn>:<lun>

For example:

  fcp:20:00:00:1f:16:bc:fe:2f:0
  fcp:20:00:52:54:00:9a:ba:bc:0

• <wwn> is the Fibre Channel Port WWN of the FCP target.
• <lun> is the SCSI LUN of the boot disk.

There is no separate syntax for FCoE, and there is no way to specify a particular network device within an FCP/FCoE SAN URI. FCoE interfaces are created automatically whenever an FCoE fabric is detected, and iPXE will search for the FCP target on all open FCoE interfaces.