Path: utzoo!mnetor!uunet!husc6!purdue!gatech!udel!rminnich
From: rminnich@udel.EDU (Ron Minnich)
Newsgroups: comp.protocols.tcp-ip
Subject: Re:  SLIP working group?
Message-ID: <1898@louie.udel.EDU>
Date: 5 Apr 88 18:45:21 GMT
References: <8803311257.AA16410@mome.cs.umd.edu>
Reply-To: rminnich@udel.EDU (Ron Minnich)
Organization: University of Delaware
Lines: 21

In article <8803311257.AA16410@mome.cs.umd.edu> steve@cs.umd.EDU (Steven D. Miller) writes:
>As of the last time I looked (SunOS 3.2), you can't turn UDP checksums on
>for NFS packets.  A code path that is completely separate from the "normal"
>UDP and IP output code paths is being taken.  Has this changed since 3.2
>came out?  How many NFS licensees are also not using checksums here?
   I got an interesting perspective on this from Sequent. Udel
just got a 10-processor Balance system, with NFS. NFS did not 
come with it, though, as shipments of NFS had been halted. The
reason, according to support people at Sequent, is that undetected
errors were making their way through their enet hardware, undetected
because checksums were turned off on NFS. The fix was to isolate
the patterns and tighten up their enet hardware. The fix was hard
because it was something like 10 patterns that occurred VERY infrequently.
I am told that NFS is shipping again from Sequent, minus errors.
We don't have ours yet, though.
   Going from Mt. Xinu 4.3 to an Ultrix system we can very easily
and very repeatably (100%) get errors just compiling files. We haven't
had a chance to track it down, but when we compile one of the X-windows
files (a small one) the .o file gets trashed. And yes, no UDP checksums.
-- 
ron (rminnich@udel.edu)