Re: Sessions dropping -- MIDRANGE-L

> 
> > We have had users that have had session drop for no apparent reason.
> The
> > sessions go to a black screen, the 400 job is still out there and it
> the
> > old "session stopped per request from the device" message is in the
> > joblog. It seems to happen at approximately the same time every day
> and
> > all of the TCP settings look fine.
> 
> Is there something that runs at that time every day?

Not to the best of my knowledge. The network folks cannot think of 
anything and there is nothing on the iSeries.
> 
> > The only change to the network setup was a recent change to the DHCP
> > service (details of which I do not know)  and even session that are
> > configured to go to the actual IP, not the name, drop.
> 
> This could be a DHCP issue.   The PC may be having it's lease revoked
> at
> that time every day.
> 
Actually, I understand the difference, even though it may not be evident 
from the statement. Going through the archives before posting this, I did 
find the DHCP lease expiration issue on a similar post and trying the 
name vs. the IP was because one of the network folks mentioned they did 
not have a internal DNS server. Just wanted to see if it made a 
difference and if the dropping sessions would have anything in common, 
like they are all setup to connect to a name.

> Based on this statement "even session that are configured to go to the
> actual IP, not the name, drop"  it appears that you have gotten DHCP
> and
> DNS confused.
> 
> DNS takes a name, and converts it to an address.   If something would
> change with DNS, it would not affect clients that are connecting
> directly
> with the IP Address.
> 
> DHCP, however, is what assigns the PCs their IP addresses (often based
> on
> the Ethernet MAC address) and has nothing to do with the names at all.
> If DHCP is making the computers change their IP address, you'll have
> the
> problem that you've described above.   Why?  Because the TCP connection
> that the TN5250 session is running in relies on two sets of addresses,
> one
> for the PC and one for the AS/400.  If one or the other of those
> addresses
> changes, the connection will stop working and eventually time out.
> 
> 
> > I tested 4 sessions on one PC, two dos telnets to name and IP and two
> CA
> > sessions to IP both and only one session dropped... Per the network
> > folks, there is no inactivity/latency setting on the router that
> these
> > go to...
> 
> As I said, this could be happening when the DHCP lease is renewed, if
> the
> PC stops communicating with the iSeries for a second, and that happens
> to
> be when the iSeries sends it's keepalive packet, it'll reset.
> 
> I was thinking also that the PC might be resetting it's TCP stack at
> that
> time, but if some of the sessions are surviving, then that's not the
> case.
> 
> >
> > Any clues?
> >
> 
> Try changing the DHCP lease time to be an hour or two longer and see if
> that helps, or changes what time the disconnects happen.   If they
> start
> happening an hour later, you know that the DHCP lease is where the
> issue
> is.
> 
> If that doesn't help, then you may have a hardware problem.   Not sure
> why
> that would happen at a regular interval, but it might be due to a power
> fluctuation or something that happens at that time every day.
> 
> That's all I can think of, right now.

I also thought of a hardware problem, but the problem is sporadic and 
happens to a lot of PCs. The only thing in common is the router, as I 
said, but per the network folks it has been up for days with no issues 
that they can see...

I will see if I can try the static IP thing and see what the lease 
expiration interval is, there probably is one, due to the security 
restrictions the company has.

Thanks for the help, Scott...

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