Ok, I'm a new network administrator, so I'm still figuring out what all our IP addresses and ranges are and whatnot, so therein lies part of my problem. To start off with, I have the following error to deal with:

Event Type: Warning
Event Source: RSVP Event
Category: None
Event ID: 10035
Description: This host can not be ACS since the Active Directory directory service has not been properly configured via the QoS ACS management console. Please configure the subnets via the QoS ACS management console.

After doing some investigation, I learned that the way to resolve this problem is to properly configure the QoS service by adding a subnet. When adding the subnet for QoS, I'm supposed to enter it in the following format:

IP address/subnet mask width in bits (for example,

So my question is: How do I figure out what to enter for the subnet? Where do I look? What about for the unmasked bits (/24 in above example)?