DHCP Error

Hi,

So, recently there was a break in our internal network at the switch in the
network closet and this pointed out a problem with Windows CE 5.0 that I
hadn't thoroughly investigated before. After a time, the device, which is
configured for DHCP assignment of a network address and plugged into a local
switch which is in turn connected to the closet switch, puts up a dialog
that says, "DHCP was unable to obtain an IP address. If the netcard is
removable, then you can remove/reinsert it to have DHCP make another attempt
to obtain an IP address for it. Otherwise, you can statically assign an
address." No surprise, right?

The problem is that DHCP does not seem to continue trying, which is a very
poor design on anything that might qualify as an "industrial device".
Further, it appears that, even if you do dismiss the dialog, you don't
recover eventually. Rebooting is not a suitable solution here, guys! Note
also that, since the network break is not at the device itself, it never
loses LINK, so there's no reestablishment of network connectivity event,
even when the network is repaired (by rebooting the switch in the network
closet).

I'm reworking NetUI, which we already customize to make the dialogs fit on
our screen, to time-out the message box for the error, but it seems that
there's an architectural error in the way things work behind the scenes as
far as retrying DHCP.

Paul T.

Paul
Tue Jul 29 16:32:28 PDT 2008

Ah, I had misread the registry documentation. It appears that setting
DhcpRetryDialogue in the registry can be used to increase the number of
retries before the system displays the dialog and DhcpMaxRetry can be used
to increase the total number of retries before giving up. Since they were
set equal, I was interpreting that as a "it's not retrying while the dialog
is shown" problem.

Paul T.

"Paul G. Tobey [eMVP]" <p space tobey no spam AT no instrument no spam DOT
com> wrote in message news:ubEA%23Gd8IHA.3736@TK2MSFTNGP06.phx.gbl...
> Hi,
>
> So, recently there was a break in our internal network at the switch in
> the network closet and this pointed out a problem with Windows CE 5.0 that
> I hadn't thoroughly investigated before. After a time, the device, which
> is configured for DHCP assignment of a network address and plugged into a
> local switch which is in turn connected to the closet switch, puts up a
> dialog that says, "DHCP was unable to obtain an IP address. If the
> netcard is removable, then you can remove/reinsert it to have DHCP make
> another attempt to obtain an IP address for it. Otherwise, you can
> statically assign an address." No surprise, right?
>
> The problem is that DHCP does not seem to continue trying, which is a very
> poor design on anything that might qualify as an "industrial device".
> Further, it appears that, even if you do dismiss the dialog, you don't
> recover eventually. Rebooting is not a suitable solution here, guys!
> Note also that, since the network break is not at the device itself, it
> never loses LINK, so there's no reestablishment of network connectivity
> event, even when the network is repaired (by rebooting the switch in the
> network closet).
>
> I'm reworking NetUI, which we already customize to make the dialogs fit on
> our screen, to time-out the message box for the error, but it seems that
> there's an architectural error in the way things work behind the scenes as
> far as retrying DHCP.
>
> Paul T.
>
>