RE: The i and DHCP

[Dan Kimmel <dkimmel@xxxxxxxxxxxxxxx>]

Right. Something else is going on.

DHCP will renew the lease for the same IP address when the lease expires as long as the leaseholder is still on the network. That's part of the DHCP spec. 

What you're describing is usually caused by somebody messing with the connections. Somebody unplugged the CAT 5 from the switch and maybe plugged it back in to the same spot on the switch or into another one. IP address might even stay the same, but the connection is broken. HTTP is connectionless, so it won't be affected. 5250 protocol is connection-oriented and it will be broken.

-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of rob@xxxxxxxxx
Sent: Thursday, October 04, 2012 9:31 AM
To: Midrange Systems Technical Discussion
Subject: Re: The i and DHCP

What we're saying is that we don't suspect it's the DHCP timeout.


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





From:   John McKee <jmmckee@xxxxxxxxxxxxxx>
To:     Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx>, 
Date:   10/04/2012 10:16 AM
Subject:        Re: The i and DHCP
Sent by:        midrange-l-bounces@xxxxxxxxxxxx



Wireless laptops exist here.  However, most of the computers I have
dealt with are still wired.  Our network person has decreed that all
computers be left on at all times.  What I could guess is that a new
DHCP lease could get assigned at 8:20 AM, while somebody was connected
to the i and working well from 7:50AM.  Suddenly, a dead connection.
This morning alone, there have been three.  User can't reconnect, as
that session is "in use" all because the IP address changed.  End the
orphan job, potentially reset the device, and all is well.

Guess what I am wondering is how other systems handle this so that
users are unaware of the IP address switch, and if the i has a way to
deal with this.  We are terminal at v5r4.

John McKee

On Thu, Oct 4, 2012 at 8:57 AM,  <rob@xxxxxxxxx> wrote:
> All of our clients use DHCP.  I did
> WRKACTJOB SBS(QINTER) SEQ(*NUMBER)
>
> Here's a couple of jobs
> Entered system:
>   Date  . . . . . . . . . . . . . . . . . . :   09/22/12
>   Time  . . . . . . . . . . . . . . . . . . :   03:39:00
> Entered system:
>   Date  . . . . . . . . . . . . . . . . . . :   09/28/12
>   Time  . . . . . . . . . . . . . . . . . . :   07:49:02
> Entered system:
>   Date  . . . . . . . . . . . . . . . . . . :   10/01/12
>   Time  . . . . . . . . . . . . . . . . . . :   05:41:15
>
> You sure they aren't using wireless laptops and roaming through dead 
spots
> or something?
>
>
>
> 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
>
>
>
>
>
> From:   John McKee <jmmckee@xxxxxxxxxxxxxx>
> To:     Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx>,
> Date:   10/04/2012 09:42 AM
> Subject:        The i and DHCP
> Sent by:        midrange-l-bounces@xxxxxxxxxxxx
>
>
>
> I haven't checked the countdown clock this morning.  Probably 28 days
> left.  So, this isn't critical.
>
> Corporate mandated switching from static addressing to DHCP.  We get
> random calls where a 5250 session cannot sign on or just quits
> working.  The corporate help desk has decided that if they receive two
> such calls, then the i just HAS to be down - despite the fact that we
> have several hundred attached and functioning workstations.
>
> Anyway, here is my question:  If a DHCP connection is established with
> the i, and then the lease on the workstation IP address expires, and a
> different IP address is subsequently assigned to the workstation
> (sorry for the wordiness).  is there any way that the i can determine
> that address for that session has changed and do something about it?
>
> I know the device description has the IP in it when a connection is
> established.  But, what happens when that address changes?
>
>
> BTW, when corporate office sends out a bogus "system down" task, they
> are done - task has been assigned.  We get the heat for taking "too
> long" to resolve the issue.
>
> John McKee
> --
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