Hi-
Earlier this week I posted about disappointing network speeds on
AlphaServer 4100's with ethernet and FDDI. Thanks to:
MJ Watson
Ivan Kristek
for replying. We also got DEC and a few other people here to look at
it. The general consensus was that while it should do the
routing/communication automatically and thus get high speeds on BOTH
fast ethernet and FDDI, this is not always the case. We had to set up
static routes for each remote host/net we wished to communicate with
on our FDDI line. This is not due to anything being wrong with the
Alphas! No one would comment on the quality of the FDDI or ethernet
networking equipment, however.
Here are a few other tips I learned along the way (and from the
responses of those listed above) in getting reliability (and not
necessarily the highest performance) out of AlphaServers with fast
ethernet and FDDI in our case:
* Disable full duplex fast ethernet. This leads to too
many packet collisions, at least with our network here.
* While this should NOT make a difference, setting the ipmtu
via ifconfig from 4352 to 1500 will greatly increase the
reliability of network intensive operations over FDDI,
especially for things like NFS. This does however slow it
down.
It is important to note that my experience is based on what I can do
at the OS level on the alphas. A more effective solution would
involve looking at the networking hardware as well.
Thanks again for the help!
--
Paul Schoenly // System Administrator // GSC NASA/GSFC
phone: 3016145931 // email: pschoen_at_janus.gsfc.nasa.gov
Received on Sat Nov 07 1998 - 01:16:37 NZDT