User Guide

Chapter 9 Customizing the portal and user logon 387
Nortel Secure Network Access Switch 4050 User Guide
• redirects client requests to an authentication page served by the portal
The DHCP server must be configured to assign the portal Virtual IP address
(pVIP) as the DNS server when the client is in the Red VLAN.
The DHCP server is configured to specify the regular DNS servers for the scopes
for the Green and Yellow VLANs. Once the client has been authenticated and is in
a Green or Yellow VLAN, DNS requests are forwarded in the regular way to the
corporate DNS servers.
For information about configuring the captive portal, see “Configuring the captive
portal using the CLI” on page 400 or “Configuring the captive portal using the
SREM” on page 416.
Exclude List
The Exclude List is a configurable list of domain names that will not be captured
by the Nortel SNAS 4050. The DNS server in the captive portal forwards requests
for domain names in the Exclude List directly to the corporate DNS servers.
In order to speed up client logon, add to the Exclude List any domain names for
URLs that are routinely accessed during client logon or startup sequences. The
Exclude List entry can be the full domain name or an expression.
By default, the captive portal Exclude List includes the following:
• windowsupdate
This will match all automatic Windows update domain names used by
browsers, for example:
• windowsupdate.com
• windowsupdate.microsoft.com
• download.windowsupdate.microsoft.com
For information about configuring the Exclude List, see “Configuring the Exclude
List using the CLI” on page 401 or “Configuring the DNS Exclude List using the
SREM” on page 418.