I have a requirement to login to NetWare 5.1 server wihtout installing Netware client. Is it possible to login to NetWare 5.1 only with Netware client by Microsoft on Pure IP ?
Yes, it is in fact possible to log into a NetWare 5.1 (or 6.x) server without installing the Novell Client for Windows. It is not possible to do this via Pure IP. The reason is because the Microsoft Client for NetWare Networks supports only the IPX protocol. So, if you install IPX on the NetWare server and the IPX protocol stack on the Windows workstation then you can use the Microsoft Client for NetWare Networks to authenticate to the NetWare server.
Personally, I wouldn't do this. The Microsoft client is pretty buggy and incredibly slow. Plus it lacks support for many Novell NetWare features such as Salvage and Purge. In addition, it only works with IPX. Add that to the fact that many third-party Novell solutions (such as CA BrightStor ARCserve for NetWare) require the Novell client to be installed.
Another option for this would be to use Native File Access (CIFS) This way your MS clients would see your NetWare 5.1 server as a Windows server and be able to access it with the native Windows tools.