EC0N@TE.CC.CMU.EDU (Eric R. Crane) (08/05/86)
First a quick description of our situation... We have 2 DECnet links from V4.2 VMS systems to V5.4 Tops-20 systems. The first link it a pair of 1Mb DMC-11's, and the other is a pair of DMR-11's at 1Mb in DMC compatability mode. What we see on our these systems when we start DECnet is the DN20 says the circuit is "starting" and the Vax says "Syncronizing". The DMC link has been in use for 5 months and just stopped working last week. That is the problem. What we have tried doing to isolate or fix these problems is check out all of the DMR's and DMC's involed by connecting them to other systems, looping back at the local system, and looping back at the remote system. All of these seem to work just fine when we are talking 20 to 20 or Vax to Vax. Has anyone else had this type of problem? We have not changed any software on any of the systems involved for over 2 months. - Eric Crnae Carnegie Mellon Computation Center -------
sy.Ken@CU20B.COLUMBIA.EDU (Ken Rossman) (08/05/86)
We have 2 DECnet links from V4.2 VMS systems to V5.4 Tops-20 systems. The first link it a pair of 1Mb DMC-11's, and the other is a pair of DMR-11's at 1Mb in DMC compatability mode. What we see on our these systems when we start DECnet is the DN20 says the circuit is "starting" and the Vax says "Syncronizing". The DMC link has been in use for 5 months and just stopped working last week. That is the problem. Has anyone else had this type of problem? We have not changed any software on any of the systems involved for over 2 months. Eric, we had this problem with a VAX at the Chemistry department (and are currently having this problem talking to you guys!). If you put a data scope on the line, you will see the following: START START STACK ACK DATA(router-init) (10 second or so pause -- timeout -- same sequence over and over again). We never did fix our problem with the Chemistry VAX -- we just put them on Ethernet instead and forgot about the VAX. As with you guys, this problem came seemingly out of nowhere and just stuck with us, no matter what we tried, it would seem. I will tell you some things that DID work, though. We originally had a KDP (DUP11/KMC11 combination) in our DN20 plugged into the DMR11 in a VAX/780. This was the combination that stopped working. We then tried plugging our DN20 into the VAX/730 at Chem, which also had a DMR11, and lo and behold, the link came up. I have no idea why, as the software running on both was supposedly the same, and I don't know what else could have been different between the 780 and the 730. So we just ran for awhile plugged into the 730, and later, swapped to an Ethernet LAN bridge and dropped the synch connection altogether. Another thing that worked on the 780 was to drop back a version of VMS. Again, I don't know what changed in that version. In any case, Eric, as I said, this seems to be what's happening between CU and CMU now, as well as (I would guess) locally at your site. You and I should get together and take a close look at the problem. /Ken -------