Why does GPIB ENET 100 stop "looking" for my DHCP server after a few minutes?

[Mark.K]

Possible reasons for failure of your ENET/100 device with your DHCP server include the following:

-The pool of available IP addresses on your device's subnet contains no more unassigned IP addresses.  You can tell that this is the problem if DHCP fails and the PWR/RDY LED continues to flicker for longer than 90 seconds at power on.

-If comunication between your DSCP and your Domain Name Server (DNS) does not occur, your device can also fail to dynamically get its IP address.  You will most likele have to contact your network administrator to see if your device's hostname has an entry in the DNS table.

There is more information about these possible causes in the "Getting Started with Your GPIB-ENET/100 and NI-488.2 for..." manual.  I referenced page 37 of the Windows 2000/NT version of this document.

Is this behavior new for your device?  Can you describe your system in more detail and if there have been any changes in your network or system that may have lead to this behavior?  Static IP addresses are easier to implement and maintain, so this might be a better way to go for you as well.  Good luck!

Message Edited by mark.kaschner on 12-12-2005 11:41 AM

[griswold]

If the computer (the DHCP server) is online at the time the GPIBENET100 boots, the DHCP server assigns the GPIPENET100 IP address and hostname just fine. No problem.

After a power-cycle and watching the GPIBENET100 unit while the computer reboots (is offline), the GPIBENET100 sends eight (8) DHCP requests (assuming they are requests) and simply stops. By the time the computer has booted, the GPIBENET100 is no longer sending anything. Experiments with the DHCP server and the DHCP server log show that once the GPIBENET100 transmits its few requests, the GPIBENET100 transmits nothing after the first minute post-power-up. This scenario is alarming for two reasons: a) when remoted, these units and the computer will not boot in sequence - the computer will boot too late to configure the GPIBENET100 b) this remote network is dynamic and static-IPs are not an option.

Perhaps there is an "initTimeout" setting in the GPIBENET100? And if so is there a way to set it?

Note, the GPIBENET100 unit has firmware vC.9 (updated by the purchaser - it was received from the factory with vB.9).

[Mark.K]

Unfortunately for your situation, the ENET/100 is designed to dynamically acquire its network IP address on power-up.  That said, you either need to make sure that the ENET/100 device powers on after the DHCP server or you must power cycle it after the DHCP server comes online.  What is most likely happening when you re-boot your DHCP server is that it sees the ENET/100 on the network and tries to assign it the new IP address, but the device is not designed to acquire its IP address dynamically at any time other than power-up.