Netware Core Protocol


Netware Core Protocol (NCP) is a network Protocol Suite from Novell INC and although usually associated with NetWare and Internetwork Packet Exchange/SPX, it is also used over TCP/IP

Netware Core Protocol (NCP) manages access to the primary eDirectory server resources.

Netware Core Protocol is used to access file, print, directory, clock synchronization, messaging, remote command execution and other network service functions.

Netware Core Protocol originally took advantage of an easy network configuration and a little memory footprint of the IPX/SPX protocol stack. Since mid-1990s the TCP/IP implementation is available.

Novell eDirectory uses NCP for synchronizing data changes between the NcpServers in a directory service tree.

Netware Core Protocol makes procedure calls to the NetWare File Sharing Protocol (NFSP) that services requests for NetWare file and print resources.

NCP Request header #

The format of the NCP Request header is shown in the following illustration. The request type is 2 bytes; all other fields are 1 byte.
  • Request type
  • Sequence number
  • Connection number low
  • Task number
  • Connection number high
  • Request code
  • Data (variable length)

Request type#

Identifies the packet type:
1111HAllocate slot request
2222HFile server request.
3333HFile server reply.
5555HDeallocate slot request.
7777HBurst mode packet (BMP).
9999HPositive acknowledge.

Sequence number#

Number used by the workstation and file server to identify packets which are sent and received.

Connection number low#

Low connection ID number assigned to the workstation.

Task number#

Identifies the operating system e.g., DOS, task.

Connection number high#

High Connection ID number assigned to the workstation. Used only on the 1000-user version of NetWare, on all other versions will be set to 0.

Request code #

Identifies the specific request function code.

The structure of the NCP Reply header is the same as the Request header, but the last 2 bytes differ after Connection Number High. This is shown in the following illustration:

  • Completion code
  • Connection status

Completion code#

The Completion code indicates whether or not the Client’s request was successful. A value of 0 in the Completion code field indicates that the request was successful. Any other value indicates an error.

Connection status#

The fourth bit in this byte will be set to 1 if DOWN is typed at the console prompt, to bring the server down.



More Information#

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