So I finished reconfiguring DPM 2007 on an SBS network. This client has ISA setup with a RADIUS client so that laptops in their office are authenticated through 802.1x.
Well I get a call and everyone has been kicked off of the wireless connection. I start digging around and see that ISA is stopped on the SBS. I start it, and it almost immediately stops again. I look in the event log and get the following error:
Date: 2/19/2009 Source: Service Control Manager
Time: 9:16:17 AM Category: None
Type: Error Event ID: 7023
The Internet Authentication Service service terminated with the following error:
Only one usage of each socket address (protocol/network address/port) is normally permitted.
For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.
I found the following blog post and followed the instructions for modifying the registry.
This article explains how ISA works, and my theory is that ISA tried to use the port for the DPM agent which is 3148-3149. I added this in addition to the suggestions on the blog. After the server came back upeverything was up and running.