IBM changed protocol for NetServer from SMB1 to SMB2 when upgraded to IBM
i 7.3.
When you are running SMB2 Windows File Explorer will refresh the list of
files shown multiple times per second. This is a violation of SMB
protocol. Microsoft admits this but currently has no plans to change
this.
Microsoft has done this in the past and have issued a hotfix. They have
no plans at this time to issue a hotfix for this occurrence.
Due to serious security issues IBM is strongly discouraging you from
configuring back to SMB1.
There is a registry hack to reduce the refresh rate. Or you can stop
using Windows File Explorer. For example, looking at a mapped drive from
a DOS prompt does not have this issue. Having a file open from a share
(like Excel, PDF, etc) does not have this issue. Just the list of files
shown in Windows File Explorer.
I will supply a link. The link talks about byte counts in netstat, etc. I
can duplicate all this.
So far the Denial of service attack only causes issues with the windows
file explorer sessions. We've not noticed other performance implications
(YMMV).
I've been told that if you're on a list of a few thousand files, and
you're updating that several times a second it gets more interesting. I'm
not in the mood to put on my steel cup, step in front of Chuck Norris and
say "prove it".
http://www-01.ibm.com/support/docview.wss?uid=nas8N1021348
IBM would like more people to report this issue to them, and to Microsoft,
to put the pressure on Microsoft to fix this.
We'll have to discuss this internally as to how we want to proceed.
Rob Berendt
midrange.com
