Re: 5250 sessions killing the system

They also said that I may want to turn off auto reconnect on those clients.

Rob Berendt
--
IBM Certified System Administrator - IBM i 6.1
Group Dekko
Dept 1600
Mail to: 2505 Dekko Drive
Garrett, IN 46738
Ship to: Dock 108
6928N 400E
Kendallville, IN 46755
http://www.dekko.com


-----Original Message-----
From: MIDRANGE-L <midrange-l-bounces@xxxxxxxxxxxxxxxxxx> On Behalf Of Rob
Berendt
Sent: Thursday, November 14, 2019 2:06 PM
To: Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxxxxxxxx>
Subject: 5250 sessions killing the system

I have this case opened with IBM. There are certain clients attaching to
the system where it starts 10,000+ port 23 (telnet) connections to our
system. All using the same 1-3 workstation id's. Totally blows our
activity level out of the water and is quite an effective denial of service
attack.

-- Some TCP connections do not spawn "jobs". Therefore we'll use a
different service.
select local_port, remote_address, count(*) as nbrconnections
from gdihq.qsys2.NS_INFO
where local_port = 23
group by local_port, remote_address
having count(*) > 10
;

Messing with things like QAUTOCFG, QAUTOVRT has ZERO effect on stopping
this.

IBM's reply has been basically put on a patch to that version of the
deprecated Client Access or upgrade to iACS.

Since most of these are Windows 7 VM sessions our Windows admins are
leaning towards the patch. When they are ready to upgrade to Windows 10 on
the 'gold' image they'll upgrade to iACS.

Rob Berendt
--
IBM Certified System Administrator - IBM i 6.1
Group Dekko
Dept 1600
Mail to: 2505 Dekko Drive
Garrett, IN 46738
Ship to: Dock 108
6928N 400E
Kendallville, IN 46755
http://www.dekko.com

--
This is the Midrange Systems Technical Discussion (MIDRANGE-L) mailing list
To post a message email: MIDRANGE-L@xxxxxxxxxxxxxxxxxx
To subscribe, unsubscribe, or change list options,
visit: https://lists.midrange.com/mailman/listinfo/midrange-l
or email: MIDRANGE-L-request@xxxxxxxxxxxxxxxxxx
Before posting, please take a moment to review the archives
at https://archive.midrange.com/midrange-l.

Please contact support@xxxxxxxxxxxx for any subscription related
questions.

Help support midrange.com by shopping at amazon.com with our affiliate
link: https://amazon.midrange.com
--
This is the Midrange Systems Technical Discussion (MIDRANGE-L) mailing list
To post a message email: MIDRANGE-L@xxxxxxxxxxxxxxxxxx
To subscribe, unsubscribe, or change list options,
visit: https://lists.midrange.com/mailman/listinfo/midrange-l
or email: MIDRANGE-L-request@xxxxxxxxxxxxxxxxxx
Before posting, please take a moment to review the archives
at https://archive.midrange.com/midrange-l.

Please contact support@xxxxxxxxxxxx for any subscription related
questions.

Help support midrange.com by shopping at amazon.com with our affiliate
link: https://amazon.midrange.com