Your basic ITPro blog... What's going on at work, what I'm interested in.

Tuesday, July 15, 2008

The Law of Unintended Consequences - Revisited

I recently commented on how we made some changes to our system that resulted in unintended consequences. Well, we got another dose of this last Saturday. Had I thought through things a bit more thoroughly, I might have caught this.

The new Cisco wireless install already required some big changes to our Checkin Kiosk computers. The changes were made, though, and the kiosks seemed to be working fine. We noticed that the wireless clients connecting to these new WAPs were getting configuration information from the Gilbert campus, even though they were on the Mesa campus. This is because we have just on Controller, which is in Gilbert.

We realized that this would mean that network traffic for these clients would all traverse our WAN link (currently a T1). Not ideal, but workable.

What we didn't realize was that this would impact event publication to our checkin kiosks. Our checkin system uses source subnet on the kiosks to determine which events to make available. Mesa events would be available on kiosks with "Mesa" IP addresses and Gilbert events would be available on kiosks with "Gilbert" IP addresses. Of course, now all kiosks were effectively in Gilbert!

So, Saturday night, as we tried to start checkin for our evening service in Mesa, our kiosks showed 'no events available'. We quickly scrambled and put our old Linksys WAPs back in place so that checkin would work.

So... more unintended consequences and, thus, more work to do.



Secret Message (The same message as before, run through the encoder again):


No comments:

Additional Info

My photo
email: support (AT) mangrumtech (DOT) com
mobile: 480-270-4332