{
  "slug": "smb-durable-handle",
  "term": "SMB durable handle",
  "aliases": [
    "SMB durable open"
  ],
  "definition": "An SMB durable handle allows a client to attempt to recover an existing file open after a network disconnect.",
  "note": "The server retains reconnectable open state subject to a timeout and original-opener authorization. It does not keep the old transport connection alive indefinitely. [open] Re-establishment uses a CREATE request with a reconnect context; the SMB 3.x form also carries the create identifier and, for a persistent open, the persistent flag. [reconnect] Recovering this state is not by itself proof that every application write is on stable storage: the protocol defines write-through separately. [write]",
  "status": "shipping",
  "advantages": [],
  "limitations": [],
  "related": [
    "smb-protocol",
    "smb-persistent-handle",
    "smb-lease",
    "io-timeout"
  ],
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "citations": [
    {
      "id": "glossary",
      "title": "Microsoft MS-SMB2 section 1.1: Glossary",
      "url": "https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-smb2/b1b7cc8a-4d24-4701-bc3f-220b543ceef8",
      "accessed": "2026-10-13"
    },
    {
      "id": "open",
      "title": "Microsoft MS-SMB2 section 3.3.1.10: Per Open",
      "url": "https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-smb2/eb446d90-a173-4797-9e83-d09490b203f4",
      "accessed": "2026-10-13"
    },
    {
      "id": "reconnect",
      "title": "Microsoft MS-SMB2 section 3.2.4.4: Re-establishing a Durable Open",
      "url": "https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-smb2/3309c3d1-3daf-4448-9faa-81d2d6aa3315",
      "accessed": "2026-10-13"
    },
    {
      "id": "write",
      "title": "Microsoft MS-SMB2 section 2.2.21: SMB2 WRITE Request",
      "url": "https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-smb2/e7046961-3318-4350-be2a-a8d69bb59ce8",
      "accessed": "2026-10-13"
    }
  ],
  "updated": "2026-10-13"
}