The NetWare Core Protocol (NCP) is a network protocol used in some products from Novell, Inc. It is usually associated with the client-server operating system Novell NetWare which originally supported primarily

MS-DOS MS-DOS ( ; acronym for Microsoft Disk Operating System, also known as Microsoft DOS) is an operating system for x86-based personal computers mostly developed by Microsoft. Collectively, MS-DOS, its rebranding as IBM PC DOS, and a few oper ...

client stations, but later support for other platforms such as Microsoft Windows, the

classic Mac OS Mac OS (originally System Software; retronym: Classic Mac OS) is the series of operating systems developed for the Macintosh family of personal computers by Apple Computer from 1984 to 2001, starting with System 1 and ending with Mac OS 9. Th ...

Linux Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, which i ...

Windows NT Windows NT is a proprietary graphical operating system produced by Microsoft, the first version of which was released on July 27, 1993. It is a processor-independent, multiprocessing and multi-user operating system. The first version of Wi ...

Mac OS X macOS (; previously OS X and originally Mac OS X) is a Unix operating system developed and marketed by Apple Inc. since 2001. It is the primary operating system for Apple's Mac computers. Within the market of desktop and lapt ...

, and various flavors of

Unix Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, a ...

was added. The NCP is used to access file,

print Printing is the process for reproducing text and images using a master form or template Print or printing may also refer to: Publishing * Canvas print, the result of an image printed onto canvas which is often stretched, or gallery-wrapped, o ...

directory Directory may refer to: * Directory (computing), or folder, a file system structure in which to store computer files * Directory (OpenVMS command) * Directory service, a software application for organizing information about a computer network' ...

clock synchronization Clock synchronization is a topic in computer science and engineering that aims to coordinate otherwise independent clocks. Even when initially set accurately, real clocks will differ after some amount of time due to clock drift, caused by clocks ...

, messaging, remote command execution and other network service functions. It originally took advantage of an easy network configuration and a little memory footprint of the

IPX/SPX IPX/SPX stands for Internetwork Packet Exchange/Sequenced Packet Exchange. IPX and SPX are networking protocol, networking protocols used initially on networks using the (since discontinued) Novell NetWare operating systems. They also became wid ...

protocol stack. Since mid-1990s the

TCP/IP The Internet protocol suite, commonly known as TCP/IP, is a framework for organizing the set of communication protocols used in the Internet and similar computer networks according to functional criteria. The foundational protocols in the suit ...

implementation is available. Novell eDirectory uses NCP for synchronizing data changes between the servers in a

directory service In computing, a directory service or name service maps the names of network resources to their respective network addresses. It is a shared information infrastructure for locating, managing, administering and organizing everyday items and network ...

tree.

Technical information

The original

implementation was provided only for Novell NetWare platform and now is obsolete. The

implementation uses

TCP TCP may refer to: Science and technology * Transformer coupled plasma * Tool Center Point, see Robot end effector Computing * Transmission Control Protocol, a fundamental Internet standard * Telephony control protocol, a Bluetooth communication s ...

/ UDP port 524 and relies on SLP for name resolution. For NCP operation in

networks the bare IPX protocol was used with Packet Type field set to 17. On the workstation (client station) side the IPX socket number of 0x4003 was used, on the server side the socket number of 0x0451. The NCP PDU has the following structure: The NCP Type field determines the type of operation: Individual requests are identified by the Sequence Number (modulo 256). The Connection Number identifies an individual client station connection on the server. Novell Netware servers of version up to 2.x supported up to 255 connections and the Connection Number occupied only 1 octet. Later it was extended to 2 octets. Task number has value 3 in requests and 1 in replies. The Data field starts with NCP Function number octet which distinguishes individual services. The contents and the length of the rest of the Data field depends on the NCP Function.

Client-side implementations

Novell Client for Windows Vista
from Novell.

from Novell.

from Novell.

from Novell.

from Novell - no longer supported.
NetWare Client for Mac OS X
from Prosoft Engineering.
ncpfs
an open-source NCP client implementation for

. * Client Service for NetWare from

Microsoft Microsoft Corporation is an American multinational corporation, multinational technology company, technology corporation producing Software, computer software, consumer electronics, personal computers, and related services headquartered at th ...

External links

NCP specification
without description of underlying Netware

RPC RPC may refer to: Science and technology * Rational polynomial coefficient * Reactive Plastic Curtain, a carbon-dioxide-absorbing device used in some rebreather breathing sets * Regional Playback Control, a regional lockout technology for DVDs * ...

framework
Wireshark (an open source protocol analyzer) Documentation - Fields of the NCP packet

{{File systems Network file systems Network protocols Novell NetWare Presentation layer protocols