Article ID: 911072 - View products that this article applies to.
When you use Dynamic Host Configuration Protocol (DHCP) Option 252 to automatically configure Microsoft Internet Explorer by using a Wpad.dat file, the DHCP clients may not obtain the configuration script.
This behavior occurs when all the following conditions are true:
This behavior occurs because the VPN Client access option is not enabled in ISA Server. By default, ISA Server controls the Routing and Remote Access service. If the VPN Client access option is not enabled in ISA Server, the Routing and Remote Access service does not start. When the Routing and Remote Access service does not start, the DHCP datagrams are not relayed to the DHCP server.
To resolve this behavior, use one of the following methods:
After you install and then configure the DHCP relay agent on a computer that is running Windows Server 2003 and then install ISA Server, the DHCP relay agent configuration is reset to the default values. You can use the Netsh utility to dump the DHCP relay agent configuration before you install ISA Server. You can then reapply the DHCP relay agent configuration after you finish installing ISA Server.
To dump the DHCP relay agent configuration by using the Netsh utility, type the following command at the command prompt:
netsh routing dump
The following is sample output of this command:
For more information about the Netsh utility, visit the following Microsoft Web site:
# ---------------------------------- # DHCP Relay Agent configuration # ---------------------------------- pushd routing ip relay uninstall install set global loglevel=ERROR add dhcpserver server=10.30.40.50 add dhcpserver server=10.30.40.51 # #DHCP Relay Agent configuration for interface "Local Area Connection" # add interface name="Local Area Connection" set interface name="Local Area Connection" relaymode=enable maxhop=16 minsecs=0 popd # End of DHCP Relay configuration
http://technet2.microsoft.com/WindowsServer/en/library/fd1e2fbe-15a6-413b-b712-28afb312c92f1033.mspxFor more information, click the following article numbers to view the articles in the Microsoft Knowledge Base:
(https://support.microsoft.com/kb/307502/ )"Automatically Detect Settings" does not work if you configure DHCP Option 252
(https://support.microsoft.com/kb/309814/ )How to configure firewall and Web proxy client Autodiscovery in Windows 2000
(https://support.microsoft.com/kb/816320/ )How to configure firewall and Web proxy client Autodiscovery in Windows Server 2003
252898For more information about how to configure the DHCP relay agent in ISA Server, visit the following Microsoft Web site:
(https://support.microsoft.com/kb/252898/ )How to enable Proxy Autodiscovery in Windows 2000
Article ID: 911072 - Last Review: December 4, 2007 - Revision: 1.6