MANAGER@SKIDMORE.BITNET (Leo Geoffrion) (11/04/88)
I'm running into a peculiar networking problem...
We have an ethernet backbone spanning three buildings with fiber
optic repeaters between the buildings and thick-wire coax within
the buildings. The net currently supports Prime and DEC minis
with no problems...
Recnetly we've begun experimenting with a configuration to support
an Appletalk cluster in one of the buildings from the computer center which is
two repeaters away (opposite end of the backbone). the intent was to
keep all of the servers in the Center where they can be centrally maintained
and serviced. We're using a Kinetics FastPath 2 to gateway between the
Appletalk and ethernets.
When we run the Appleshare at the remote site, the VAX computers begin to log
communication errors on the ethernet line. More importantly, about every
3 to 5 days, one of the VAX units goes into a "networking storm" -- bouncing
adjacency up and down about 100 times in a few minutes. It then settles
down with no operator intervention and runs fine for another several days.
We've tried a number of measures...
a. changed the KFP configuration from TCP/IP to simple Appletalk
b. DEC field service replaced the ethernet controller on the VAX.
c. Swapped the KFP with a different unit.
d. Consulted DEC support, who had no constructive suggestions.
e. consulted Kinetics support who say that they've never heard
of DECnet/Kinetics interaction problems.
None of these things have produced any improvement in the problem.
And now some questions....
1. Has anyone seen similar problems? any suggestions of what
to test next?
2. Is anyone providing AppleShare file service across ethernet
repeaters in a mixed vendor environment? Can we just be trying
to get too much performance out of the net?
3. Do you have any recommendations for additional test equipment
(such as lan analyzers...) that we should bring to task. We
don't have any on hand, but mgmt. is desperate enough to
authrorize the $$.
I appreciate any and all suggestions. We're getting stumped on this one.
===================================================================
Leo D. Geoffrion
Associate Director for NYNEX: (518) 584-5000 Ext. 2628
Academic Computing BITNET:
Skidmore College MANAGER@SKIDMORE (for personal mail)
Saratoga Springs, NY 12866 LDG@SKIDMORE (for newsletters)