{
  "slug": "world-wide-name",
  "term": "World Wide Name (Fibre Channel)",
  "aliases": [
    "World Wide Name",
    "WWN",
    "Fibre Channel WWN"
  ],
  "definition": "In Fibre Channel, a World Wide Name is a persistent 64-bit name for an entity such as a node or port, distinct from a port's fabric address.",
  "note": "WWPN names a port and WWNN names a node. RFC 4338 distinguishes a nonvolatile port name from the volatile 24-bit N_Port_ID used for communication. These identify different aspects of the connection, not interchangeable representations of a logical volume. [rfc4338-names] [linux-fc-names]\n\nLinux's NPIV documentation assigns responsibility for virtual-port WWN allocation and uniqueness to the managing administrative entity. The name is not evidence of hardware authenticity or permission to write; that is an engineering boundary, not a claimed security property of the identifier. [linux-fc-names]\n\nDo not automatically equate an FC WWPN with a multipath WWID. The pinned multipath-tools manual groups paths by a selected WWID obtained through its configured identification method, including udev attributes. A port name by itself does not select which logical unit behind that port is intended. [multipath-identity]",
  "related": [
    "fibre-channel",
    "scsi-device-identification",
    "multipath-io"
  ],
  "citations": [
    {
      "id": "rfc4338-names",
      "title": "RFC 4338 (January 2006), section 2.2: Fibre Channel identifiers and login",
      "url": "https://www.rfc-editor.org/rfc/rfc4338.html#section-2.2",
      "accessed": "2026-11-03"
    },
    {
      "id": "linux-fc-names",
      "title": "Linux v6.12: SCSI FC transport documentation, virtual-port names and administrative uniqueness responsibility",
      "url": "https://raw.githubusercontent.com/torvalds/linux/v6.12/Documentation/scsi/scsi_fc_transport.rst",
      "accessed": "2026-11-03"
    },
    {
      "id": "multipath-identity",
      "title": "multipath-tools at d53932bdbee02f440518ea384e63d7c4d3f66685: multipath.conf(5), uid_attribute and WWID generation",
      "url": "https://raw.githubusercontent.com/opensvc/multipath-tools/d53932bdbee02f440518ea384e63d7c4d3f66685/multipath/multipath.conf.5.in",
      "accessed": "2026-11-03"
    }
  ],
  "status": "shipping",
  "advantages": [],
  "limitations": [],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "updated": "2026-11-03",
  "provenance": [
    "Primary documentation and pinned implementation review on 2026-11-03; no device interrogation, failover experiment or global-uniqueness measurement."
  ]
}