swb@CHUMLEY.TN.CORNELL.EDU (02/09/89)
We're having a weird experience here -- apparently if we put our Annex terminal servers, or RT PCs, on one of two Cabletron multiports, they can get to everything on the local ethernet but they can't get through their local p4200 (old ethernet board). I don't know about other systems, but Annexes and RTs which are directly connected to the ethernet work fine. Has anyone seen anything like this before? Should I beat up the multiport or the p4200 first? Thanks ... Scott
medin@NSIPO.NASA.GOV ("Milo S. Medin", NASA ARC NSI Project Office) (02/09/89)
The old IL 3010 is likely a IL 3010A, a V1 controller. The Cabletron transciever does not properly handle version 1 devices (ignore what the manufacturer says). Using an IL 3010B or p4215 will work fine with the MT-800. But I can't get the MT-800 to deal properly with V1, even on old Vax controllers. Thanks, Milo
ccruss@deneb.ucdavis.edu (0059;0000000000;230;9999;98;) (02/09/89)
Scott, Yes, I saw the same thing between a Develcon terminal server and an old ethernet board on a p4200 using a multiport. Very strange. When I used a DELNI in the place of the Multiport the problem went away, so I supected the Multiport at the time. Shortly thereafter we upgraded to the new Proteon Ethernet boards and switched back to the multiport and haven't seen any problems since so I didn't follow up on it. Russ
mead@UHURA.CC.ROCHESTER.EDU (Ted Mead) (02/10/89)
Scott, We had the same problem when connecting our NYSERNet Proteon router, with an Interlan 3010B (old Ethernet Interface, to one of our backbone MT-800s. The problem has to do with the signalling coupling between the Ethernet interface and the MT-800. The Interlan uses DC coupling while the MT-800 is an AC coupled device. For some odd reason, howerver, you can hook up a DEC DELNI to the Proteon (old Ethernet interface) and that works find. It wasn't really clear if the Annex, RT PCs, and p4200 was the problem so if this wasn't the answer that you were interested in I apologize. Incidently, the newer version of the Interlan interface (3010A) works fine with the MT-800. You can select AC or DC coupling with that interface. Also, a good person to contact at Cabletron is Mike Hart (800)526-8378. He is aware of this problem and if you want a more indepth explaination, he could probably help you. Thanks, Ted
swb@CHUMLEY.TN.CORNELL.EDU (02/10/89)
Thanks, all. I thought we had a 3010B in that interface, but everybody's right, it's a 3010A, which is certainly the problem. Scott
jch@SONNE.TN.CORNELL.EDU (Jeffrey C Honig) (02/10/89)
I don't know if it was clear in this discussion, but the Proteon Ethernet in question is not directly connected to the MT-800. The Proteon is connected to a DELNI which is connected to Thickwire. There are two Cabletron's involved, one is also directly connected to the Thickwire, the other one is on the far side of a fiber Ethernet extender. Does the AC/DC coupling problem apply in this case? I was under the impression that that would only affect the communications between the Ethernet controller and Ethernet transceiver. As as correction to Scott's original posting, the Proteon Ethernet board in question is a p4213 Interlan NI3010A, not a p4214. Jeff
medin@NSIPO.NASA.GOV ("Milo S. Medin", NASA ARC NSI Project Office) (02/10/89)
Hmmm, that is interesting. I have had problems with 3010A's dealing with DELNI's in the past (the DELNI takes some other shortcuts as well that can occaisionally cause problems with Interlan controllers). Try things with the 3010B, which should work. Who knows what the problem could be. The spec says that the 3010A is V1 and that the DELNI is V2, and thus things shouldn't play. Why it doesn't work is secondary to the central issue I think... thanks, Milo
jch@TCGOULD.TN.CORNELL.EDU (Jeffrey C Honig) (02/10/89)
Well the problem has been resolved, switching from a p4213 to a p4214 fixed it. Note that the problem was not just with a Cabletron MT-800, it also showed up with a fiber transceiver extender. Thanks everyone for your help! Jeff
tef@cgl.ucsf.edu (Thomas Ferrin%CGL) (02/10/89)
One of the strangest problems I ever had concerned connecting up a new Excelan multiport transceiver to a network via an old Interlan NT10 transceiver. This was on a large network with many machines. When the MPT was attached to the xceiver *some* pairs of hosts (which were *not* connected to the MPT) experienced extreme (80%) packet loss. Other hosts ran just fine. The hosts connected to the Excelan MPT ran fine. Attaching a Sniffer to the net showed that all of the missing packets where there on the wire, it was just some hosts conuldn't receive them. There were no CRC errors, no runt packets, etc. A TDR showed nothing unusual. It took days of troubleshooting to isolate the problem. I do not know of a logical explanation for this type of mysterious behavior, but I do know to avoid mixing old and new spec equipment now.
medin@NSIPO.NASA.GOV ("Milo S. Medin", NASA ARC NSI Project Office) (02/10/89)
I think the old NT10 was a version 1 transciever, and the Excelan (BICC) MPT is version 2. Thanks, Milo