Cisco Cisco Clean Access 3.5

Manually enter subnet and netmask – To specify the desired network address and netmask 
manually. If selected, the Subnet and NetMask fields appear at the bottom of the form.Inherit 
Scoped Global Options — This field is only visible if DHCP options are enabled and is turned 
on by default. If this field is disabled, the scoped global options configured in the Global 
Options tab are not inherited.

Click Update when finished. If there are errors in the configuration, warning messages appear. 
Follow the instructions to correct the settings. 

By automatically generating subnets, you can quickly divide your network into small segments. 
Segmenting your network into small subnets can be an effective security measure in response to a worm 
attack, since a network comprised of many small subnets (with one host per subnet possible) limits the 
ability of clients to engage in peer-to-peer interaction. 

The recommended maximum number of subnets per Clean Access Server is 1000. If the CAS machine 
has sufficient memory (>1G), up to 2500 subnets can be configured. Do not exceed the recommended 
limit if this will place an excessive burden on system resources, particularly server memory. 

First, make sure that the IP pools you want to add are in the range of a managed subnet. If needed, 
add the managed subnet under Device Management > CCA Servers > Manage [CAS_IP] > 
Advanced > Managed Subnet (for details, see 

).