Information Technology Reference
In-Depth Information
Security:
By specifying a callback number, unauthorized users cannot connect remotely
to your system from their own location. All calls will be connected only at the location
(phone number) to which the server returns the call.
Cost savings:
The remote user will only make a brief call to the remote access server. The
remote access server will then place a call back to the user, meaning that the organiza-
tion providing the server will pay for any time-based connection charges rather than the
end-user having to pay these charges.
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Note
Callback is offered only for dial-in connections; it is not available for VPN connections.
Another feature of user-based remote access settings is the ability to assign a static IP
address to the user that will be consistent at each remote access session. This setting is one way
to overcome the fact that remote access clients do not truly query the DHCP server for addresses,
and can therefore not take advantage of DHCP reservations to receive the same IP address for
each session. If you want your end users to consistently receive the same address, you can
configure your user account settings to provide this.
RRAS caches IP addresses received in batches from the DHCP server but does not cache
the usual DHCP scope options, such as WINS and DNS server lookups. See Recipe 4-6,
“Configuring IP Settings,” for more information relating to this topic.
■
Note
The ability to assign static IP addresses to remote access users exists only in native-mode
Windows 2000 or Windows 2003 domains. If you run in a mixed mode, this feature will be disabled.
See Also
Microsoft KB 303684: “How to Configure IP Reservations for RRAS Clients in
Windows 2000.” This article provides a summary of the IP address reservation
process when using RRAS.
Microsoft Windows XP Professional Product Documentation: “Callback” (
http://
www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/
using_callback.mspx
).
Microsoft TechNet: “Callback” (
http://technet2.microsoft.com/WindowsServer/f/?en/
Library/ed9c2d7e-2752-4abb-ac71-a63e184c9e391033.mspx
). This article describes the
callback mechanism as viewed by the server.
