In article <[log in to unmask]>, [log in to unmask] u (Aaron Porter) writes: > Paging through the latest Linux kernel I came across DECnet support. > It seems that the one and only person working on DECnet support is > progressing rapidly. My question is what's so great about DECnet? What > would speaking DECnet allow a UNIX box to do that it doesn't already? DECnet is the native networking protocol for OpenVMS. DECnet is similar to TCP/IP in many ways. It runs on top of Ethernet, FDDI, ATM, and other network infrastructures. It has objects which are similar to ports on TCP/IP. It's got something similar to INETD (a connection comes in on a port/object and automatically is handled by a particular program). DECnet does not have an equivalent to DNS, though. Each node must know the address of every other node. In addition, DECnet's addresses scheme is only 16-bit (maximum of 65536 nodes) as opposed to TCP/IP's 32-bit implementation (over 4 billion nodes). I'm not sure about the Linux implementation, but DECnet on OpenVMS is very well tied into the OS rather than being a layer on top. For example, DECnet is tied into the file system very well. With this, I can use any file on any DECnet node as if it were a local file. For example, from MiaVX1, I could issue a command like: $ TYPE MUMR2"kacovert mypassword"::LOGIN.COM This will display the LOGIN.COM file in KACOVERT's account (using the password mypassword) on the MUMR2 (Middletown) OpenVMS system. If something called proxies were enabled between the systems, I wouldn't even need the username and password (similar to a .RHOSTS). This is different from something like RCP, because the file isn't copied to MiaVX1 first, it's just accessed as if it were a local file. This is also different from NFS in that I don't have to configure the file system for each computer I want to access files from. I just have to let DECnet know about the other computer. Miami stopped running DECnet natively on our network in January, 1996. This was the beginning of an ongoing process to eliminate protocols on our network. Eventually, Miami would like to reduce our network to just IP protocols (the only protocols left on our network that I'm aware of are IP, AppleTalk, and IPX/SPX). In January, 1996, we began tunnelling DECnet over TCP/IP between our OpenVMS systems. The tunnelling protocol we're using is a Cisco (now Process Software) proprietary protocol. Unless the Linux port implements this proprietary protocol, you will not be able to use DECnet at Miami. -- Kent Covert, Software Coordinator Miami Computing and Information Services Miami University, Oxford, OH [log in to unmask]