VPDN Process Overview
Figure 21-1 shows the VPDN process. To help decipher and better understand the later discussion of configuring VPDNs, the VPDN process is described briefly in this section.
Step 1. | A dialup client connects to a LAC/NAS through ISDN or analog service. |
Step 2. | The client and the LAC/NAS negotiate the PPP
LCP options such as PAP or CHAP, PPP multilink, compression, and so on. |
Step 3. | If CHAP has been agreed upon, the LAC/NAS queries the client with a CHAP challenge. |
Step 4. | The client responds with username@DomainName and the password. |
Step 5. | Using local VPDN configuration or contacting an AAA server, the LAC/NAS determines whether the client is a VPDN user based on the domain name in the CHAP response. |
Step 6. | If the client is ... |
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