Access Control Concepts

ProCurve NAC 800

VLAN 3

IP address = 192.168.12.1/24 IP address = 192.168.13.1/24

Restricting Access in the Quarantine Subnet. The NAC 800 uses one of these methods to enforce the quarantine:

It does not assign quarantined endpoints a default gateway in their DHCP configuration, and it sends them subnet masks of 255.255.255.255. In effect, each quarantined endpoint is isolated within a subnet that consists of itself alone. To allow access to remediation services, the NAC 800 sends the endpoints static routes to itself. It then acts as DNS server, as well as proxy Web server to the allowed sites.

Network infrastructure devices enforce static ACLs that drop all traffic from quarantined addresses except that to remediation services.

N o t e

If you select the static ACL option, you must ensure that the infrastructure

 

devices are capable of filtering traffic correctly. For example, if you

 

multinetted quarantine subnets on VLANs, the device should be able to

 

apply ACLs to multinetted traffic. If you have assigned quarantined end-

 

points IP addresses on existing subnets, the infrastructure devices must

 

be able to filter non-routed traffic. For example, the Switch 3500yl/5400zl/

 

6200yl Series supports VLAN ACLs, which filter all IP traffic regardless of

 

whether it is switched or routed.

 

 

Inline Deployment Method

As with other deployment methods, the NAC 800 tests endpoints for compliance with NAC policies and decides to grant or deny network access accordingly.

An inline NAC 800 also enforces its decisions. It imposes a firewall between endpoints on either side of its Ethernet port 1, which connects to the private network, and port 2, which connects to endpoints to be tested. Endpoints on the port 2 side cannot access any resources on the port 1 side—until the NAC 800 has checked them and ensured they comply with NAC policies. Therefore, typically, the NAC 800 is deployed at a “choke point” such as a VPN gateway, where all valuable resources are located beyond the NAC 800’s port 1.

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