O$ - Determine if machine is using DHCP

Steve Farmer hts at hts.com.au
Mon Apr 6 20:39:36 EDT 2009

Hi Doug

You hit the nail on the head

We use Mark Philip's ODB Admin tool for the server setup and my idea was 
to interrogate the machine when the app is booted and if the machine is 
using DHCP, to at least warn the user of potential trouble that this can 

Of course one can never solve all these issues, but at least we can try !

I like the idea of this tool also displaying the IP address of the server


Doug Easterbrook wrote:
> from the answers to the list, it seems that the requirement comes from 
> the age old problem of helping users find their database server and 
> not being able to rely on the server being at any one specific address.
> it seems to me that having DHCP enabled may reduce the chance of the 
> service moving to a different ip address, but not necessarily. The 
> only thing that mitigates the issue is if you can make the ip address 
> static. DNS's are nice, but not easy for an end user to set up.
> a small philosophical thought before a suggestion to solving this. I 
> use the concept anytime I'm faced with where to help the user help 
> themselves. There are 3 possible controls in any system:
> - 'detective' - detect that an error condition exists
> - 'preventative' - prevent the error condition from ever occurring
> - 'corrective' - allow the user to correct the error condition
> if we rely only on one of the control measures exclusively, it does 
> not a good system make. eg: suppose we prevent negative numbers in a 
> field and make all sorts of assumptions in our code that the number 
> will be positive (preventative measure). and then suppose somebody 
> inserts a negative number using SQL - if we have no 'detective' 
> measures to find the issue, then the code assuming positive numbers is 
> unprotected and our code is in deep trouble.
> thats a bit of an aside, but it might apply in this case.
> if we prevent running the odb (or simply warn them) unless they have a 
> static ip, then we are going to be in trouble down the road regardless.
> We do know from the client perspective, when they cannot connect to 
> the ODB (or any database for that matter), because we get an error 
> condition from the code
> I might suggest that the better answer in this case is to build a 
> network scanner for the subnet to go look for the 
> service you want on all machines on the network. That way you can pop 
> up and say 'looks like the server moved ... did you mean yyy machine'.
> that way you can help them help themselves.
> or... have a tool running on the server (perhaps omnis) that gets 
> 'LocalIPAddr' and displays it on the screen. Call it the ODB console 
> if you need to. That way, if somebody cannot connect, you just tell 
> them to go see what the number is and then type it in to the client.
> just a thought. Perhaps not elegant - but I do think fighting DHCP 
> might be the wrong control avenue on this one.
> Doug Easterbrook
> Arts Management Systems Ltd.
> mailto:doug at artsman.com
> http://www.artsman.com
> Phone (403) 536-1205 Fax (403) 536-1210
> On Apr-4-09, at 11:00 AM, omnisdev-en-request at lists.omnis-dev.com wrote:
>> out of interest, why does it matter (or whats the business purpose) of
>> how the machine gets its ip?
>> you can get static addresses from DHCP bound to a mac address or
>> dynamic ones.
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