iSCSI Glossary

iSCSI Qualified Name (IQN)

iSCSI uses the iSCSI Qualified Name (IQN) scheme for addressing. IQN's are made up of four distinct fields separated by a period . and can be created/used by any organization that owns a domain name (known as the the naming authority).

The four fields are:

The string iqn. - this distinguishes the name from an eui. formatted name.
A date in the format YYYY-MM, for example 1995-10. - this must be a valid year/month combination, corresponding to when the naming authority first owned the domain (used in the next field).
The DNS domain of the naming authority in reverse, for example com.high-availability
A optional string prefixed by a : that the naming authority deems appropriate. Effectively this string provides detail to the IQN and can include product types, serial numbers etc. It can also include a colon : as a boundary separator. For example storage:jbod1, storage:jbod2 or 02:b11f6a06-c9bd-cfeb-ea26-885a25d080c4.

Here are some examples of valid IQN addresses:

iqn.1995-10.com.high-availability:02:b11f6a06-c9bd-cfeb-ea26-885a25d080c4

iqn.2001-04.com.high-availability:storage.clusterA.jbod7

iqn.2001-04.com.high-availability

Extended Unique Identifier (EUI)

iSCSI also allows another form of addressing managed by the IEEE Registration Authority. This type of addressing represents a globally unique identifier (EUI) and is assigned by the registration authority. The format of the EUI consists of the string eui. followed by a EUI-64 identifier (16 ASCII-encoded hexadecimal digits).

Here are some examples of valid EUI addresses:

eui.0567AH88952981FF

eui.ACC5412369875DAG

Typically EUI's are used by manufacturers who are registered with the IEEE Registration Authority and use the EUI-64 scheme for its worldwide unique names (the EUI-64 is also used in other network protocols, such as Fibre Channel, which defines a method of encoding the EUI-64 it into the World Wide Name used by FC as a unique identifier).