Radius Vlan Support - Cisco ASR 5000 Series Administration Manual

GGSN Support in GPRS/UMTS Wireless Data Services
In the event that a single server becomes unreachable, the system attempts to communicate with the other servers that
are configured. The system also provides configurable parameters that specify how it should behave should all of the
RADIUS AAA servers become unreachable.
The system provides an additional level of flexibility by supporting the configuration RADIUS server groups. This
functionality allows operators to differentiate AAA services for subscribers based on the APN used to facilitate their
PDP context.
In general, 128 AAA Server IP address/port per context can be configured on the system and it selects servers from this
list depending on the server selection algorithm (round robin, first server). Instead of having a single list of servers per
context, this feature provides the ability to configure multiple server groups. Each server group, in turn, consists of a list
of servers.
This feature works in following way:
All RADIUS authentication/accounting servers configured at the context-level are treated as part of a server
group named "default". This default server group is available to all subscribers in that context through the
realm (domain) without any configuration.
It provides a facility to create "user defined" RADIUS server groups, as many as 399 (excluding "default" server
group), within a context. Any of the user defined RADIUS server groups are available for assignment to a
subscriber through the APN configuration within that context.
Since the configuration of the APN can specify the RADIUS server group to use as well as IP address pools from which
to assign addresses, the system implements a mechanism to support some in-band RADIUS server implementations (i.e.
RADIUS servers which are located in the corporate network, and not in the operator's network) where the NAS-IP
address is part of the subscriber pool. In these scenarios, the GGSN supports the configuration of the first IP address of
the subscriber pool for use as the RADIUS NAS-IP address.
Important:
Reference.

RADIUS VLAN Support

VPN customers often use private address space which can easily overlap with other customers. The subscriber addresses
are supported with overlapping pools which can be configured in the same virtual routing context.
This feature now allows Radius Server and NAS IP addresses to also overlapping without the need to configure separate
contexts, thereby simplifying APN and RADIUS configuration and network design.
This feature now allows Radius Server and NAS IP addresses to also overlapping without the need to configure
separate contexts, thereby simplifying APN and RADIUS configuration and network design.
This feature supports following scenarios to be defined in the same context:
Overlapping RADIUS NAS-IP address for various RADIUS server groups representing different APNs.
Overlapping RADIUS server IP address for various RADIUS servers groups.
Previously, the above scenarios were supported, albeit only when the overlapping addresses were configured in different
contexts. Moreover a static route was required in each context for IP connectivity to the RADIUS server.
OL-22944-02
For more information on RADIUS AAA configuration, refer AAA Interface Administration and
Cisco ASR 5000 Series Gateway GPRS Support Node Administration Guide ▄
Features and Functionality - Base Software ▀