3Com OfficeConnect 3C16771, User Manual, Page: 111 / 182

Automatic Proxy Forwarding 111
clicking Login , the password is verified using MD5
authentication. The password is never sent ”in the clear”
over the Internet, preventing password theft and replay
attacks.
Once authenticated, remote users can access all IP
resources on the LAN, and users on the LAN can bypass the
Web Site Filter. The connection closes if user inactivity on
the connection exceeds the configured time-out period. In
that case, the remote user must re-authenticate. If it seems
like authentication is failing for no reason, make sure that
the Caps Lock key on the keyboard is not on.
NAT must not be enabled for remote authenticated access.
Automatic Proxy Forwarding
A proxy server intercepts all requests to the Web server to
see if it can fulfill the requests by returning a locally stored
copy of the requested information. If not, the proxy:
■
Completes the request to the server
■
Returns the requested information to the user
■
Saves it locally to fulfill future requests
Because of this, a proxy can improve Internet response and
lessen the load on the Internet link. For example, suppose a
school is using the Internet for a research project. A student
requests a certain Web page, and then sometime later, a
second student requests the same page. Instead of
forwarding the request to the Web server where the page
resides, the proxy server returns the local copy of the page
that it already fetched for the first student.
The problem with a proxy server is that each client must be
configured to support the proxy, which adds to
administration tasks.
If a proxy server is already installed on the LAN, instead of
configuring each client to point to the proxy server, move it
to the WAN and enable Automatic Proxy Forwarding. The
Internet Firewall can automatically forward all Web proxy
requests to the proxy server without client configuration.
As a result, no client configuration is required when a Web
Proxy is used.