matt@oddjob.UChicago.EDU (Matt Crawford) (05/13/87)
Help! We want to connect our campus IP networks to SPAN, a wide
area decnet network run by NASA. At the moment our sole SPAN
node is a PDP-11 with a 9600 baud leased line. We will shell
out for a microvax if we can put some sort of software on it
that will provide access from TCP as transparently as possible.
Is there anything which will give us better access than just
logging in to the span node? Some people will want to transfer
very large data sets and buying enough scratch disk for them
would be an obstacle. Most users don't want to learn VMS (and
DECNET/Ultrix only supports ethernet as an interface).
What we wish for is a protocol translator. Is there one?
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Matt University matt@oddjob.uchicago.edu
Crawford of Chicago {astrovax,ihnp4}!oddjob!mattejnorman@uwmacc.UUCP (Eric Norman) (05/14/87)
In article <3770@oddjob.UChicago.EDU>, matt@oddjob.uchicago.edu (Matt Crawford) pleads for mercy with: > Help! We want to connect our campus IP networks to SPAN, a wide > > Is there anything which will give us better access than just > logging in to the span node? Some people will want to transfer I just copied a file from a DECnet host to an IP host using a MicroVAX running Ultrix as an intermediary with rsh ultrix-host dcat decnet-node::vms-file > unix-file All I needed was an .rhosts file on the Ultrix beast. A proxy account on the DECnet node does not seem to allow referencing a file relative to your home directory; i.e., the following failed: rsh ultrix-host dcat decnet-node::login.com However, this does work after an rlogin to the Ultrix host: dcat decnet-node::login.com | rsh unix-host put vms-login-file where my .cshrc on unix-host aliases "put" to "cat - >". Now, methinks you would want to write some simple shell scripts to do all that, but I reckon you would want to do that anyway so that folks don't have to learn VMS. > What we wish for is a protocol translator. Is there one? Heffalumps. See RFC875; such a critter operating at the network or transport layer would probably be considered miraculous. However, up at the presentation or application layer it seems at least partly possible. Gatewaying mail from DECnet squawkers to IP barkers isn't difficult, albeit without complete protocol translation. The above would be another example of the possibilities. I think one of the nice things about the .rhosts or proxy account approach is that they allow you hide the fact that you're rising higher up the protocol stack. Eric Norman Internet: ejnorman@unix.macc.wisc.edu UUCP: ...{allegra,ihnp4,seismo}!uwvax!uwmacc!ejnorman Life: Detroit!Alexandria!Omaha!Indianapolis!Madison!Hyde "And on the eighth day He said, 'Oops'." -- me --
JERRY@STAR.STANFORD.EDU (05/14/87)
I don't know if this will help, but Van Jacobsen at LBL developed an interface called DBRIDGE that allows IP packets to be sent over DECNET. The way it works is the two hosts on either side of a DECNET link install this software that uses DECNET mailboxes to communicate between them. The packets that they are transferring are IP packets. Then a dummy interface is put into the kernel that knows to give IP packets to the dbridge process for transmission over DECNET. Both Wollongong and SRI products make this software available. Jerry
melohn@sluggo.UUCP (05/17/87)
In article <1505@uwmacc.UUCP> ejnorman@unix.macc.wisc.edu.UUCP (Eric Norman) writes: > >I just copied a file from a DECnet host to an IP host using >a MicroVAX running Ultrix as an intermediary with > > rsh ultrix-host dcat decnet-node::vms-file > unix-file > We do this all the time with our Sunlink DNA gateway. I define the following: alias sethost on -i dna-gateway dnalogin !$ in my .cshrc, and then can remotely login from any Unix node in our internet to any DECnet node accesable via the Sunlink DNA DECnet gateway "dna-gateway" with the following command: sethost decnetnode Similar aliases can be setup for file transfer, the "on" utility exporting your filesystem enviornment to the gateway machine via NFS, which is handy when you are transfering multiple files.
mouse@mcgill-vision.UUCP (05/31/87)
In article <8705141842.AA28803@ucbvax.Berkeley.EDU>, JERRY@STAR.STANFORD.EDU writes: > [...] Van Jacobsen at LBL developed an interface called DBRIDGE that > allows IP packets to be sent over DECNET. The way it works is the > two hosts on either side of a DECNET link install this software that > uses DECNET mailboxes to communicate between them. The packets that > they are transferring are IP packets. Then a dummy interface is put > into the kernel that knows to give IP packets to the dbridge process > for transmission over DECNET. Fascinating. Sounds just like what I wrote to perform exactly the same function (except I called mine `dnip'). Initial version looked like point-to-point links; current version is a "virtual Ethernet" - a full broadcast interface. Not very efficient in its use of DECnet resources though; it keeps O(n*n) DECnet connections open all the time, where n is the number of hosts on the virtual Ethernet. (Eventually, of course, I intend to fix this.) > Both Wollongong and SRI products make this software available. And if anyone wants a non-commercial version (with the benefits and the disadvantages thereof), send me mail. At present I have it running only on MicroVAX Ultrix 1.2; I can't promise anything else. (Requires source to install without nasty hackery.) der Mouse (mouse@mcgill-vision.uucp)