Designing Access Controls

Choose RADIUS Servers

Table 3-74. Integrated Server/Proxy to Turnkey Combination for the NAC 800

PEPs with Built-in PDPs

Proxy PDP with Policy/ Credential

 

 

Repository

 

 

 

AP 530

NAC 800 managed by IDM and using its local

Wireless Edge Services Module

database

 

 

 

 

Choosing between these options is similar to choosing between them for

 

traditional RADIUS servers (see “Choose Which Devices Will Play the

 

Role of PDP” on page 3-79):

 

a. Do you have an existing directory service?

 

If yes, you should use that directory; choose general or integrated

 

server/proxy. (The general option tends to be more scalable.)

 

 

N o t e

There is one exception: your existing directory service is Active

 

Directory, and you want to use digital certificates to authenticate

 

users. The NTLM protocol, which the NAC 800 uses to query Active

 

Directory, only supports MS-CHAPv2 and PEAP with MS-CHAPv2. So

 

in this case, you must use the NAC 800’s local database; choose

 

turnkey server or integrated server/proxy to turnkey server.

 

If no, choose turnkey server or integrated server/proxy to turnkey

 

 

server. (The integrated server/proxy to turnkey server option tends

 

to be more scalable.)

b.How large is your network?

If you have a large network (over 1000 wired and 500 wireless users per LAN and over 3000 total users in the LAN), you should add a directory service and choose the general option.

3.How many NAC 800s does your network require?

The NAC 800’s endpoint integrity services are the limiting factor, not its RADIUS services. Each NAC 800 (CS or ES) can test up to 3000 endpoints.

Take a closer look at the number of users and endpoints you anticipate in your network. Although users may shift from location to location, partic- ularly in a wireless zone, the NAC 800s can respond to requests from any location, just like any other RADIUS server.

In the PCU example, the APs for the library and the plaza typically support a maximum of 600 users. The RPs that handle the private wireless zones can have up to 5000 users at one time, whereas the private wired zone handles traffic for up to 11,000 users. With 16,600 users, this network

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