KVC@ENGVAX.SCG.HAC.COM (Kevin Carosso) (06/27/87)
I've got a VAXstation-2000 up and running here (fun little system).
In getting the CMU/Tek TCP/IP code up on it I've run into a problem.
I've traced the problem to it's root... Apparently the VS-2000 never receives
ARP broadcast packets. It receives other packets with the ARP protocol
type and can send ARP broadcast packets. It just never receives any. In
fact, near as I can tell, the VS-2000 never receives any ethernet broadcast
packets. It does receive multicast packets.
It makes no difference whether the VS-2000 is running as a LAVC satellite
node or completely standalone off it's own disk. It speaks LAVC, DECnet,
and LAT with no problems. All these use multicasts but never broadcasts,
right? Also, if I have our Berkeley 4.3 UNIX machine act as an ARP server
for the VS-2000, the CMU TCP/IP works just fine.
The VS-2000 is our only thinwire ethernet node, so it's on the thinwire side of
a DEMPR which is plugged into a transceiver on our thick ethernet. Maybe the
DEMPR is not passing through broadcast packets? The DEMPR is plugged into a
Cabletron ST-500 transceiver. I think our other DEC equipment is on H4000s,
so maybe that's at fault? If not, that would leave the DESVA controller
or the VMS device driver...
Any clues anyone?
/Kevin Carosso kvc@engvax.scg.hac.com
Hughes Aircraft Co. kvc%engvax@oberon.usc.edu
ps. The CMU TEK/TCP code runs without modification on the -2000. Since
the ethernet device name is ESA0: you need to define XEA0 as a logical
name for it. I modified the code to avoid such tackiness. In my
version you specify a driver family name (XE for all DEC ethernet)
and a device name (ESA0:). I will be sending this (and other mods)
to the TEK-TCP list (if the list still works).JERRY@STAR.STANFORD.EDU (06/29/87)
You are right, the DESVA (ethernet controller on the 2000) will not receive ANY broadcast packets. This is because DEC has decided to disable this functionality except for those ports that specifically ask for it (via the multicast address option or by setting the multicast state to be on). DEC recommends the multicast address option (MLA). DEC also plans to make this a standard across all ethernet cards, so processes like CMU's and mine (Wollongong) will have to change. Anyway, all you need to do for a quick solution is to turn MLT state on when you are allocating your DESVA port and broadcast packets will be accepted. Jerry Scott