Layer 4 Redirect Applications; Configuring Isg Layer 4 Redirection; C H A P T E R 4 Redirecting Subscriber Traffic Using Intelligent Service Gateway Layer 4 Redirect - Cisco 10000 Series Configuration Manual

Chapter 4 Redirecting Subscriber Traffic Using Intelligent Service Gateway Layer 4 Redirect
When traffic is redirected, ISG modifies the destination IP address and TCP port of upstream packets to
reflect the destination server. For downstream packets, ISG changes the destination IP address and port
to the original packet's source.

Layer 4 Redirect Applications

The Layer 4 Redirect feature supports the following applications:
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Configuring ISG Layer 4 Redirection

Three options exist for applying Layer 4 redirection to sessions:
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The following tasks describe how to configure Layer 4 redirection. The first task is optional. One or more
of the next three tasks is required. The last task is optional.
For examples of Layer 4 redirection configuration for specific applications (such as unauthenticated user
redirect), see the
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OL-14660-03
TCP redirection for unauthenticated users and unauthorized services—HTTP traffic from
subscribers can be redirected to a web dashboard where the subscribers can log on so that
authentication and authorization can be performed.
Initial and periodic redirection for advertising captivation—Subscriber traffic can be redirected to a
sponsor's web page for a brief period of time at the start of the session or periodically throughout
the session.
Redirection of application traffic—Application traffic from a subscriber can be redirected so as to
provide value-added services. For example, a subscriber's SMTP traffic can be redirected to a local
mail server that can function as a forwarding agent for the mail.
Domain Name System (DNS) redirection—DNS queries may be redirected to a local DNS server.
In some deployments, such as public wireless LAN (PWLAN) hotspots, subscribers may have a
static DNS server addresses, which may not be reachable at certain locations. Redirecting DNS
queries to a local DNS server allows applications to work properly without requiring
reconfiguration.
Configure redirection directly on a physical main interface or logical subinterface.
Configure a service profile or service policy map with the Layer 4 redirect attribute in it, and apply
that service to the session.
Configure the Layer 4 redirect attribute in the user profile.
"Configuration Examples for ISG Layer 4 Redirect" section on page
Defining a Redirect Server Group, page 4-4
Configuring Layer 4 Redirection on an Interface, page 4-4
Configuring Layer 4 Redirection in a Service Policy Map, page 4-6
Configuring Layer 4 Redirection in a Service or User Profile on the AAA Server, page 4-7
Verifying ISG Traffic Redirection, page 4-7
Cisco 10000 Series Router Access Network Control Protocol Configuration Guide
Configuring ISG Layer 4 Redirection
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