Access Control Concepts

ProCurve NAC 800

Because remediation is a key component of an endpoint integrity solution, the NAC 800 does not follow this strategy. Instead, it places quarantined endpoints in a subnet that exists in the private network, albeit in carefully controlled way.

You can establish the quarantine subnet in one of these ways:

The NAC 800 assigns to quarantined endpoints IP addresses that are valid but unused in the production network. The quarantined “subnet” is not truly a subnet, but rather an unused subset of an existing subnet.

For example, the network includes three Class C user subnets, each with 100 users:

10.1.2.0/24

10.1.3.0/24

10.1.4.0/24

The DHCP server assigns users addresses in the 25 to 125 range—for example, 10.1.2.25 to 10.1.2.125. The second half of each subnet (10.1.X.128/25) is available for quarantined endpoints:

Quarantine “subnet” = 10.1.2.128/25

Quarantine “subnet” = 10.1.3.128/25

Quarantine “subnet” = 10.1.4.128/25

Of course, the scopes on the network DHCP server must exclude these addresses so that a healthy endpoint is not inadvertently assigned an address in the quarantined subset.

The network administrator multinets the quarantine subnet on an existing VLAN. Each VLAN requires its own quarantine subnet.

For example, the network includes two Class C subnets, each with

250 users:

192.168.8.0/24

192.168.12.0/24

A quarantine subnet isolates non-compliant endpoints from each existing subnet:

Quarantine subnet = 192.168.9.0/24

Quarantine subnet = 192.168.13.0/24

The network administrator sets up multinetting on infrastructure devices to accommodate the quarantine subnets. For example, a routing switch could have this configuration:

VLAN 2

IP address = 192.168.8.1/24 IP address = 192.168.9.1/24

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